Mentaiko Butter Stir-Fried Udon

Name: Mentaiko Butter Stir-Fried Udon
Prep time: 12 min
Cook time: 8 min
Total time: 20 min
Yield: 2 servings
Cuisine: Japanese
Ingredients: 14 oz (400 g) frozen or vacuum-packed udon noodles, 2 blocks (about 7 oz / 200 g each); 3 oz (85 g) mentaiko (spicy cod roe), slit each sac open lengthwise and scrape out the roe with a spoon; discard the thin skin; 3 tbsp (42 g) unsalted butter, divided into 2 tbsp (28 g) and 1 tbsp (14 g); 2 cloves (8 g) garlic, finely minced; 1 tbsp (15 ml) Japanese soy sauce; 1 tbsp (15 ml) mirin; 2 tbsp (30 ml) sake or water; 3 whole (45 g) scallions, thinly sliced, whites and greens kept separate; 1 sheet (3 g) nori sheet, cut into thin strips with shears; 1 tbsp (15 ml) neutral oil; ½ whole (60 g) lemon, cut into 2 wedges for serving (optional)

From the MyKitchenBank Kitchen

Chewy udon noodles are tossed in a hot skillet with browned-edge butter, a splash of soy and mirin, and creamy spicy cod roe (mentaiko) that is gently cooked through to a safe 145°F (63°C) and turns opaque and coral pink. Finished with nori and scallion, it's a savory, briny 20-minute dinner.

Prep: 12 min
Cook: 8 min
Total: 20 min
Makes: 2 generous servings

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Ingredients

2 servings

14 oz (400 g) frozen or vacuum-packed udon noodles, 2 blocks (about 7 oz / 200 g each)
3 oz (85 g) mentaiko (spicy cod roe), slit each sac open lengthwise and scrape out the roe with a spoon; discard the thin skin
3 tbsp (42 g) unsalted butter, divided into 2 tbsp (28 g) and 1 tbsp (14 g)
2 cloves (8 g) garlic, finely minced
1 tbsp (15 ml) Japanese soy sauce
1 tbsp (15 ml) mirin
2 tbsp (30 ml) sake or water
3 whole (45 g) scallions, thinly sliced, whites and greens kept separate
1 sheet (3 g) nori sheet, cut into thin strips with shears
1 tbsp (15 ml) neutral oil
½ whole (60 g) lemon, cut into 2 wedges for serving (optional)

Equipment (6)

12-inch (30 cm) nonstick or carbon-steel skillet or wok
Medium pot for boiling udon
Small bowl
Rubber spatula or wooden spoon
Kitchen shears or sharp knife
Instant-read thermometer

Steps

Before you start

Use frozen (sanuki-style) or vacuum-packed udon; both work, and frozen has the best chew.
Mentaiko is cured and lightly salty, so the sauce is seasoned lightly. Taste before adding extra soy.
This recipe cooks the mentaiko to a safe internal temperature of 145°F (63°C); keep an instant-read thermometer handy.
Have everything prepped and next to the stove; the stir-fry takes only about 5 minutes.

1
Prep the toppings
- Slice the scallions, keeping whites and greens in separate piles.
- Mince the garlic.
- Cut the nori into thin strips.
- Slit the mentaiko sacs lengthwise, scrape the roe into a small bowl, and discard the skins.
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Ready when: Roe is loose and skins are discarded.
Tip: Chilled mentaiko is easier to slit and scrape than room-temperature roe.
2
Make the sauce base
- To the bowl of roe, add 1 tbsp (14 g) of the butter, softened if possible, and mash with a spoon into a loose paste.
- Combine the soy sauce, mirin, and sake in a separate cup and set both beside the stove.
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Ready when: Roe and butter form a speckled pink paste.
Tip: Mixing the roe with butter first helps it coat the noodles evenly instead of clumping.
3
Loosen the udon
- Bring a medium pot of water to a boil.
- Add the udon and cook 1 to 2 minutes for frozen blocks, or 30 to 60 seconds for vacuum-packed, gently separating strands with chopsticks.
- Drain well in a colander.
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Ready when: Noodles separate easily and are hot but still firm.
Tip: Do not fully cook the noodles; they finish in the skillet and will turn soft otherwise.
4
Sauté the aromatics
- Heat the oil in a 12-inch (30 cm) skillet over medium-high heat until shimmering.
- Add the remaining 2 tbsp (28 g) butter and the scallion whites.
- Stir for 30 seconds, then add the garlic and stir 15 seconds more.
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Ready when: Butter foams and the garlic smells fragrant but is still pale golden.
Tip: If the garlic darkens to brown, it turns bitter. Lower the heat or start over.
5
Stir-fry the noodles
- Add the drained udon and toss for 1 to 2 minutes so the noodles pick up some butter and a few spots of light browning.
- Pour in the soy, mirin, and sake mixture and toss for another 1 minute until the liquid is mostly absorbed and the noodles look glossy.
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Ready when: Noodles are glossy, hot, and little to no liquid pools in the pan.
Tip: Use a spatula and tongs or chopsticks together to lift and toss gently so the noodles don't tear.
6
Cook in the mentaiko
- Reduce the heat to low.
- Add the mentaiko-butter paste and toss constantly for 1 to 2 minutes, until the roe turns opaque and coats the noodles.
- Check the roe-coated noodles with an instant-read thermometer; the roe should reach 145°F (63°C).
- Turn off the heat.
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Ready when: Roe is opaque pale pink, coats the noodles like a creamy sauce, and reads 145°F (63°C) on an instant-read thermometer.
Tip: Keep the noodles moving and the heat low so the roe cooks evenly and doesn't turn dry and grainy; add a teaspoon of water if the sauce looks tight.
7
Finish and serve
- Taste and add a few drops of soy if you want more salt.
- Divide between two warm bowls and top with the scallion greens and nori strips.
- Serve right away with lemon wedges, if using.
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Ready when: Nori is crisp on top and the noodles are steaming.
Tip: Add the nori at the last second, since it softens quickly in the steam.

Good to know

Tips

Use a large skillet so the noodles can toss freely; a crowded pan steams the noodles rather than frying them.
Draining the noodles well keeps the sauce from becoming watery.
For extra heat, add a pinch of shichimi togarashi or chili flakes with the garlic.
A soft-cooked egg on top makes it even richer; use a fully cooked or pasteurized egg if you want to avoid raw egg.

Make ahead

Prep the scallions, garlic, nori, and mentaiko-butter paste up to 1 day ahead and refrigerate separately. Cook the noodles just before serving.

Storage & reheating

Best eaten immediately. Refrigerate leftovers in an airtight container up to 1 day. Reheat in a skillet over medium heat with 1 tbsp water for 2 to 3 minutes until steaming hot throughout (at least 165°F / 74°C). Not recommended for freezing once the roe is added.

Substitutions

mentaiko (spicy cod roe) → tarako (unseasoned salted cod roe) plus 1/2 tsp chili flakes. Add an extra pinch of salt or a few drops of soy to taste, and cook to 145°F (63°C) as well.
frozen or vacuum-packed udon noodles → dried udon or spaghetti. Cook according to package directions to just shy of tender; spaghetti gives a wafu-pasta style dish.
sake or water → water or dashi. Dashi adds a little extra savory depth.
nori sheet → kizami nori or furikake. Use about 1 tbsp furikake in place of the strips.