Let's make the mentaiko sauce. Make a shallow cut along the karashi-mentaiko. Scrape off the roe with a spatula, removing the outer film.
Place the mentaiko into a large bowl. Add the lemon juice and 3 to 4 drops of soy sauce. Mix with a balloon whisk. This will help cover the fishy smell of the mentaiko.
Add the olive oil a little at a time and mix with the whisk. Now, the sauce is done!
Let's prepare the toppings. Remove the stems of the shiso leaves and roll them together. Cut the roll in half, line them up and thinly shred the shiso.
Lightly rinse them with water to reduce any bitterness and strain well. Wrap the shiso with a paper towel and thoroughly remove the excess water.
The skin of the daikon radish has a pungent taste and rough texture so remove it with a knife.
Place the daikon perpendicular to a ceramic grater and grate it in a circular motion. This will help make the grated daikon smooth and delicious. Gather the daikon toward the center and tilt the grater to drain the excess liquid.
Let’s cook the pasta. Put the salt into a large pot of boiling water. Place the pasta in the pot and as it softens submerge it with the tongs. Lightly stir to prevent the pasta from sticking together. Cooking time depends on the type of pasta so follow the directions on the package.
Let’s remove the pasta. For al dente, remove the spaghetti 1 minute before the stated cooking time and strain the pasta with a mesh strainer.
Place the pasta into the bowl of the mentaiko sauce. Add a spoonful of the remaining cooking water to moisten.
Quickly toss to coat with the sauce and place the mentaiko spaghetti onto a plate. Pour the remaining sauce onto the pasta.
Place the shiso leaves and lightly squeezed daikon radish on top. Sprinkle on the black pepper and the Parmesan cheese. Finally, garnish with the shredded toasted nori seaweed.
The lemon juice is essential to bring out the flavor of the mentaiko.
A cold version of this recipe is also a must-try recipe in summer. Cook the pasta a bit longer, rinse it with water like udon noodles and mix with the cold mentaiko sauce.