How to Cook Costco Yakisoba Stir Fry

The Kirkland Signature Yakisoba Stir Fry Kit is a refrigerated meal found in Costco’s deli section.

It contains pre-cooked sous vide chicken, fresh vegetables, wheat noodles, and two packets of soy-based yakisoba sauce.

Package weight runs around 3.5 pounds. Feeds 4-6 people easily.

Costco also sells a frozen version from Ajinomoto in the freezer aisle. That one is vegetarian and comes in individual 9oz pouches.

This guide covers stovetop cooking for the fresh deli kit, plus microwave and stovetop methods for the frozen version.

Total cook time ranges from 3 minutes (frozen, microwave) to 10 minutes (fresh deli kit, stovetop).

You’ll need a large wok or 12-14 inch skillet, vegetable oil, and a spatula.

Product Details

Product: Kirkland Signature Yakisoba Stir Fry with Seasoned Chicken

Type: Refrigerated, pre-cooked (ready to heat)

Package Size: 3.5 lbs (4-6 servings)

Price: $5.99-$6.49 per lb / approximately $20-$23 per package at Costco

Storage: Refrigerate at 40F or below

Calories per Serving: 240 (per 6.75 oz serving)

Main Ingredients: Sous vide chicken thighs, yakisoba noodles, broccoli, red onion, celery, carrots, snap peas, bell peppers, soy-based sauce

Item Number: 81505

Frozen Version Details

Product: Ajinomoto Vegetable Yakisoba

Package Size: 6 x 9oz pouches

Price: $14.99-$15.99 per box at Costco

Calories per Serving: 410 (per 9 oz pouch)

Item Number: 464292

Cooking Methods Comparison

Recommended Method: Stovetop for the fresh deli kit produces the best texture with tender-crisp vegetables and properly heated chicken.

Method 1: Stovetop for Fresh Deli Kit (Recommended)

This Japanese noodle stir fry cooks in under 10 minutes on the stovetop.

The package says 5 minutes. Realistically, you need 8-10 minutes for everything to heat through properly.

Use a large pan. The 3.5 pounds of ingredients need room to move.

Step 1: How Do You Prepare the Product?

Separate all ingredients into individual bowls before cooking.

The vegetables sit on top in the container. Chicken and noodles are underneath.

Instructions:

1. Remove lid and separate vegetables, chicken, noodles, and sauce packets into individual bowls
2. Check vegetables for freshness. They should look crisp, not wilted

Equipment: Large wok or 12-14 inch saute pan, spatula or tongs, 3-4 prep bowls

Step 2: What Temperature and Time Do You Use?

Medium-high heat with 2 oz of oil gets the best results.

The oil helps vegetables cook without burning and gives noodles a slight crispness.

Instructions:

1. Heat wok or large skillet to medium-high
2. Add 2 oz oil (about 1/4 cup or 4 tablespoons)
3. Wait until oil shimmers before adding ingredients

Temperature: Medium-high heat (setting 7-8 out of 10)

Time: 8-10 minutes total

Step 3: When Do You Add Each Ingredient?

Vegetables go first. They need the most time to soften slightly while staying crisp.

Chicken is already cooked. It just needs heating through.

Instructions:

1. Add vegetables to hot oil. Cook 2-3 minutes, stirring occasionally
2. Add chicken. Cook another 2 minutes
3. Add noodles and ONE sauce packet. Toss everything together for 2-3 minutes
4. Taste. Add second sauce packet only if you want more salt

Checkpoint: At the 5-minute mark, vegetables should be starting to soften at edges

Step 4: How Do You Know When It’s Done?

Steam rising from the pan and noodles glistening with sauce means you’re close.

Cut a piece of chicken to check internal temperature if you want to be certain.

Instructions:

1. Check that steam rises from the entire pan
2. Verify chicken is hot throughout (insert thermometer into thickest piece)
3. Noodles should be coated evenly with sauce and slightly glossy

Target Temperature: 165F internal for chicken

Visual Indicator: Sauce coats noodles evenly, vegetables are bright in color with slightly softened edges, steam rising

Method 2: Microwave for Frozen Yakisoba

The Ajinomoto frozen vegetable yakisoba is designed for microwave cooking.

Three minutes and you’re eating. The pouch cooks right in the bag.

This method is best for quick lunches or when you need a single serving fast.

Step 1: How Do You Prepare the Frozen Package?

The 9oz pouch has a tear tab in the corner for venting.

Instructions:

1. Remove one 9oz pouch from the box
2. Tear off tab “A” (corner tab) to create a vent
3. Place pouch on a microwave-safe plate

Equipment: Microwave, microwave-safe plate, fork or chopsticks

Step 2: What Power Level and Time?

Full power for 3 minutes in a standard 1100-watt microwave.

Instructions:

1. Microwave on HIGH for 3 minutes
2. Let rest inside microwave for 1 minute (steam continues cooking)

Power Level: HIGH (100%)

Time: 3 minutes plus 1 minute rest

Step 3: How Do You Serve?

The bag is extremely hot after cooking. Handle carefully.

Instructions:

1. Carefully remove plate from microwave (use oven mitt if needed)
2. Tear off tab “B” to fully open the bag
3. Pour noodles onto plate or into bowl

Checkpoint: Steam should billow out when you open the bag fully

Step 4: How Do You Know When It’s Done?

Noodles should be hot throughout with no frozen spots in the center.

Instructions:

1. Stir noodles and check center is steaming hot
2. If cold spots exist, return to microwave for 30 seconds

Visual Indicator: Steam rising from entire portion, noodles separated and glossy with sauce

Method 3: Stovetop for Frozen Yakisoba

The stovetop method takes longer but lets you add extra ingredients.

Good option if you want to bulk up the meal with rotisserie chicken or extra vegetables.

Step 1: How Do You Prepare the Frozen Package?

You’ll add the frozen disc directly to boiling water.

Instructions:

1. Add 1 cup water to a non-stick skillet
2. Bring water to a boil over high heat
3. Tear off tab “B” to open the package

Equipment: Non-stick skillet, spatula, 1 cup measuring cup

Step 2: What Temperature and Time?

High heat to start, then medium to finish.

Instructions:

1. Place frozen noodle disc vegetable-side down in boiling water
2. Cook on high heat for 6 minutes
3. Flip noodles over
4. Reduce to medium heat. Stir for 3-4 minutes until water evaporates

Temperature: High heat (6 min), then medium heat (3-4 min)

Time: 9-10 minutes total

Step 3: When Do You Add Extra Ingredients?

After flipping is the right time to add leftover chicken or extra vegetables.

Instructions:

1. After flipping, add chopped rotisserie chicken or extra vegetables
2. Add 1/4 cup more water if noodles seem dry
3. Stir everything together as water evaporates

Checkpoint: Water should be mostly evaporated by the 9-minute mark

Step 4: How Do You Know When It’s Done?

All water evaporated and noodles heated through.

Instructions:

1. No visible water in the pan
2. Noodles are hot throughout when tested with fork
3. Vegetables are heated and slightly tender

Visual Indicator: Dry pan, steaming noodles, sauce coating everything evenly

Safety and Quality Indicators

Food Safety

• Internal Temperature: 165F minimum for the chicken
• Steam Check: Product should steam when stirred
• Thawing: Do not thaw frozen yakisoba before cooking. Cook from frozen
• Fresh Kit: Cook within 3-4 days of purchase. Check the sell-by date

Quality Indicators (Done Properly)

• Color: Noodles should be dark brown with sauce. Vegetables should be bright, not dull
• Texture: Vegetables tender-crisp, not mushy. Noodles slightly chewy, not soggy
• Temperature: Hot throughout, above 165F
• Appearance: Sauce evenly distributed, slight gloss on noodles

Signs of Overcooking

• Vegetables are completely soft and dull in color
• Noodles stick together in clumps
• Chicken becomes dry or rubbery
• Sauce reduces and becomes too thick or burns on pan edges

Serving Suggestions

Portion Size: About 1.5-2 cups per person (package makes 4-6 servings)

Serving Ideas

• Serve in deep bowls. Top with sesame seeds and sliced green onions
• Add a fried egg on top for extra protein
• Squeeze fresh lime juice over the finished dish
• Pair with how to cook Costco edamame as a side

Pairing Recommendations

• Steamed Costco jasmine rice on the side
• Costco egg rolls as an appetizer
• Costco potstickers alongside
• Costco spring rolls for variety
• If you want more protein, add Costco frozen shrimp to the stir fry

Storage and Reheating

Leftover Storage

• Refrigerate within 2 hours of cooking
• Store in an airtight container
• Consume within 3-4 days
• Do not freeze cooked yakisoba. Noodles become mushy when thawed

Reheating Instructions

• Microwave: 1-2 minutes on HIGH, stirring halfway
• Stovetop: 3-4 minutes over medium heat with a splash of water or soy sauce
• Target Temperature: 165F

Troubleshooting Common Issues

Issue: Yakisoba is too salty

Cause: Used both sauce packets. The sauce contains 1010mg sodium per serving

Solution: Start with one sauce packet only. Taste before adding the second. Add extra vegetables to absorb excess salt

Issue: Noodles stick together in clumps

Cause: Not enough oil or not stirring enough during cooking

Solution: Use the full 2 oz (1/4 cup) of oil. Toss and stir continuously once noodles hit the pan

Issue: Vegetables are too soft or mushy

Cause: Overcooked or pan not hot enough, causing steaming instead of stir frying

Solution: Make sure oil is shimmering hot before adding vegetables. Cook for 2 minutes maximum before adding chicken

Issue: Chicken is cold in the center

Cause: Large chicken pieces need more time. Package directions underestimate cook time

Solution: Cut large chicken pieces in half before adding to pan. Use a meat thermometer to verify 165F

Issue: Not enough room in pan

Cause: Pan is too small for 3.5 pounds of ingredients

Solution: Use a 12-14 inch skillet or 7-quart wok. Or cook in two batches

Product Variations and Related Items

Similar Costco Products

• Ajinomoto Vegetable Yakisoba (Frozen) – Vegetarian option, individual pouches, microwave-ready
• Kirkland Signature Chicken Chow Mein – Similar concept, different noodle style and sauce
• Kirkland Signature Beef Chow Mein – Beef version of the chow mein option
• Try Costco frozen ramen for a soup-based noodle dish
• Or Costco udon noodles for thicker Japanese noodles

Other Quick Costco Meals

• Costco fried rice pairs well with yakisoba
• Costco orange chicken for another Asian-inspired option
• Costco teriyaki chicken shares similar flavor profiles
• Costco bulgogi for Korean-style variety

Cooking Time Adjustments

Fresh deli kit takes 8-10 minutes on stovetop. No air fryer or oven method recommended.

Frozen Ajinomoto takes 3 minutes in microwave or 9-10 minutes on stovetop.

Adding extra vegetables to either version adds 1-2 minutes to cooking time.

Which Method Should You Choose?

Choose Stovetop (Fresh Kit) when:

• You want the best texture with crisp vegetables
• Cooking for 4-6 people
• You have a large wok or skillet available
• You want to customize with extra vegetables

Choose Microwave (Frozen) when:

• Speed is the priority (3 minutes)
• Cooking for 1-2 people
• You want vegetarian yakisoba
• Minimal cleanup is needed

Choose Stovetop (Frozen) when:

• You want to add rotisserie chicken or extra vegetables
• Slightly crispier texture is preferred
• No microwave available

Time Comparison

Microwave Frozen (3 min) < Stovetop Fresh (8-10 min) < Stovetop Frozen (9-10 min)

Texture Ranking

Stovetop Fresh (crispiest vegetables, best overall) > Stovetop Frozen (good) > Microwave Frozen (softest)

FAQ on How To Cook Costco Yakisoba Stir Fry

How Long Does It Take to Cook Costco Yakisoba Stir Fry?

The fresh Kirkland Signature yakisoba kit takes 8-10 minutes on the stovetop.

Package directions say 5 minutes. That’s optimistic.

The frozen Ajinomoto version cooks in 3 minutes by microwave or 9-10 minutes on the stovetop.

Can You Cook Costco Yakisoba in an Air Fryer?

Not recommended for this Japanese noodle dish.

The sauce and noodles need a wok or skillet to heat properly. Air fryers would dry out the yakisoba noodles and burn the soy-based sauce.

Stick with stovetop cooking for the best stir fry results.

How Many Servings Are in the Costco Yakisoba Stir Fry Kit?

The 3.5-pound package feeds 4-6 people depending on appetite.

Official nutrition lists 8 servings at 6.75 oz each. Realistically, most adults eat double that amount.

Plan for 4 generous portions or 6 smaller ones.

Is the Chicken in Costco Yakisoba Already Cooked?

Yes. The seasoned chicken thighs are fully cooked using sous vide method.

You’re just reheating the meat, not cooking it raw. Still verify internal temperature reaches 165F before serving for food safety.

Why Is My Costco Yakisoba So Salty?

The yakisoba sauce packets contain 1010mg sodium per serving.

Using both sauce containers doubles that. Start with one packet only. Taste before adding more.

Adding extra vegetables like broccoli or snap peas helps absorb excess salt.

Can You Freeze Costco Yakisoba Stir Fry?

The fresh deli kit is not meant for freezing.

Cook it within 3-4 days of purchase. Freezing causes the vegetables to become mushy and noodles soggy.

The Ajinomoto frozen version is already designed for freezer storage.

What Size Pan Do I Need for Costco Yakisoba?

Use a 12-14 inch skillet or 7-quart wok minimum.

The 3.5-pound package needs room. A crowded pan steams instead of stir fries. If your pan is smaller, cook in two batches.

Is Costco Yakisoba Stir Fry Healthy?

Mixed results. Each serving has 240 calories, 15g protein, and fresh vegetables.

The downside is high sodium content. The wheat noodles contain gluten. Not keto-friendly due to 29g carbs per serving.

What’s the Difference Between Fresh and Frozen Costco Yakisoba?

The fresh deli kit includes sous vide chicken, raw vegetables, and wheat noodles.

The frozen Ajinomoto version is vegetarian with pre-cooked noodles and vegetables in sauce. Different products entirely.

Can You Add Extra Protein to Costco Yakisoba?

Absolutely. The stir fry works great with added protein.

Toss in Costco shrimp or sliced Costco tofu for variety. Leftover rotisserie chicken works too. Add protein when you add the noodles.

Conclusion

Knowing how to cook Costco yakisoba stir fry makes weeknight dinners simple. The whole process takes under 10 minutes.

Use one sauce packet to control sodium. Get your wok or skillet hot before adding oil.

The fresh deli kit beats takeout on price and cooking time. Around $20 feeds a family of four with leftovers.

Add extra vegetables like bok choy or mushrooms to stretch the meal further. The tender chicken and chewy noodles work with almost any Asian-inspired additions.

Quick, filling, and way cheaper than restaurant stir fry.