You're looking at two membrane sacks stuffed with salted, chili-seasoned eggs from a fish called suketōdara, or Alaska pollack, or mentai. Hungry yet?
This is what mentaiko ("mentai babies") looks like when you buy it in the supermarket. It's a common onigiri (rice ball) filling in Japan and occasionally pops up in things like bi bim bap or pizza, but one of the most popular and, in my opinion, most delicious ways to eat mentaiko is on pasta, typically in a butter- or cream-based sauce.
This may seem strange. When I told a friend in the U.S. about the "fish egg pasta" popular in Japan, she thought I meant some kind of fish-flavored egg noodles, maybe a variation of squid ink noodles. When I told her I actually meant pasta topped with fish eggs, I think she may have briefly considered never emailing me again. But mentaiko, and especially mentaiko pasta, deserve a try. The salting and chili-seasoning process produces something a little spicy and not very fishy, with a flavor all its own. Heck, I'll even go so far as to say mentaiko is my favorite of all the fish roes! You heard it here first, people.
I've eaten mentaiko pasta in restaurants and at the home of a mentaiko-obsessed friend, and it seemed time for me to try making it myself. I used the recipe in Harumi's Japanese Cooking
It took less than ten minutes to put the sauce together -- squeezing the mentaiko out of the membranes was strangely gratifying -- and the finished dish was nearly as good as and several pounds lighter than the incredible cream-based version served at one of the cafes in my town. Next time I'll look for darker red mentaiko, as the usually-shocking-pink sauce is part of the allure for me. And I might throw in some mushrooms as well. Perhaps there's a mentaiko pizza in my future?
Some notes on ingredients: If you can't get mentaiko, make a nice eggplant parmesan or something; there are no substitutes. See the notes about shiso here. Kombu cha powder is a hard one. Harumi recommends using a strong fish stock as a substitution, but maybe you could mix kelp powder (available at health food stores) with some matcha powder. Or just throw in some parmesan cheese. The kombu cha is just there to add umami anyway.
Mentaiko Pasta
Adapted from Harumi's Japanese Cooking
Serves 2
6 oz/170 g uncooked thin pasta (such as spaghettini)
3 oz/85 g mentaiko
2 tablespoons butter
1/2 teaspoon kombu cha (kelp tea) powder
2 small sheets of nori, cut into matchstick-sized pieces (about 2 tablespoons)
3 shiso leaves, finely shredded
chopped green onion or chives, to garnish
soy sauce, if needed
Boil the pasta in salted water according to package directions. While it is cooking, soften the butter for 10-20 seconds in the microwave, then beat until creamy. Remove the roe from the membrane and mix into the butter. Add the kombu cha powder and stir until smooth. It will resemble buttercream frosting at this point, but resist the urge to eat it straight from a spoon.
When the pasta is al dente, drain and immediately mix with the butter mixture, tossing to coat the pasta evenly. Taste for seasoning and, if necessary, add a little soy sauce. Divide onto two plates and top with the shiso, nori and a sprinkling of green onions or chives.
Thanks for the comment. We don't do much of this but, would like to.