Step 1

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.

Step 2

With a knife, make a lengthwise slit through each mentaiko sac membrane and scrape out the spicy roe (you can use a spoon, too). Discard the sac membrane.

Step 3

In a large bowl, combine the mentaiko, heavy cream, and soy sauce and mix them all together.

Step 4

Cut the squid into small bite-sized pieces.

Step 5

Next, mince the onion: Lay a peeled onion half 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.

Step 6

Stack the shiso leaves, roll them up, and cut into julienned strips. Set aside until serving.

Step 7

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

Step 8

Season the onion with the salt and sauté until caramelized and golden brown.

Step 9

Next, add the squid and 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.

Step 10

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

Step 11

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

Step 12

Add the 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.

Step 13

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

Step 14

Serve the Mentaiko Udon on individual plates and garnish with the shredded nori and shiso leaves.

Step 15

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