Gather all the ingredients. Bring a large pot of water to a boil for cooking the udon noodles. While you‘re waiting for the water to boil, prepare the other ingredients and cook the sauce.

With a knife, make a lengthwise slit through each menbrane of 2 sacs spicy salted pollock roe or cod roe (karashi mentaiko). Scrape out the spicy roe (you can use a spoon, too). Discard the membrane.

In a large bowl, combine the mentaiko, ¼ cup heavy (whipping) cream, and 1 tsp soy sauce and mix them all together.

Cut 4 oz squid into small bite-sized pieces.

Next, mince ½ onion. Lay a peeled half onion on the cutting board, flat side down. With the knife tip pointing toward the root end, make thin vertical slices to within ½ inch of the root end. Then, with the knife edge toward the root end, make several horizontal slices, again keeping the root intact. Finally, make perpendicular cuts down through the vertical slices you made.

Stack 10 shiso leaves (perilla/ooba), roll them up, and cut into julienned strips. Set aside until serving.

Heat a frying pan over medium heat. When it‘s hot, add 2 Tbsp unsalted butter. Once the butter has melted, add the minced onion.

Season the onion with ⅛ tsp Diamond Crystal kosher salt and sauté until caramelized and golden brown.

Next, add the squid and 2 Tbsp sake. Sauté the squid until cooked through, about 2 minutes. When cooked, the squid will be firm and opaque white. Do not overcook the squid or it will turn tough.

Season the mixture with freshly ground black pepper and cook for 1–2 more minutes.

Add the squid mixture into the bowl with the mentaiko sauce and mix well.

Add 2 servings udon noodles to the pot of boiling water and cook according to the package instructions. I use frozen Sanuki udon and it requires cooking for 1 minute. Dried udon noodles will take more time to cook. Tip: I recommend using only frozen or fresh udon noodles for their thicker and chewier texture.

Quickly drain the cooked noodles and transfer them to the mentaiko sauce. Toss well until the noodles are evenly coated with the sauce.

Serve the Mentaiko Udon on individual plates and garnish with shredded nori seaweed (kizami nori) and the shiso leaves.

Mentaiko is raw and it‘s not recommended to reheat it. Therefore, make this recipe only for the portion you‘re going to serve.