Mentaiko is a new obsession. The ones I can find in New York come from Japanese or Korean speciality food stores and are whiting roes cured in salt, Korean red chilli flakes and a little ground sesame seed. I believe you can also find cod or pollock roes cured in the same way but I'm not sure if you can taste any difference in the type of fish used.
I like to eat them as a snack, membrane and all, cut into chunks and seasoned with a little yuzu or lemon juice and a few grind of fine white pepper. They are very salty though so not everyone would agree.
For the less salt-addicted among us these mildly spicy, briny eggs make a fantastic sauce for pasta, creating a Japanese spin on spaghetti alla bottarga.
300g linguine, I like the fine-sized variety
4 lobes (2 pairs) mentaiko
2 tbsp butter
2 tbsp extra virgin olive oil
2 shiso leaves, rolled and finely shredded
Yuzu or lemon juice
1 tbsp salt
White pepper, finely ground
What to do
Bring a large pot of water to a rolling boil, add the salt and then the pasta when the water is boiling again. Cook according to the packet's instructions.
Make a cut in the membrane of each roe sac and gently squeeze the eggs into a small bowl. Discard the membrane. Melt the butter until it liquefies and stir it into the mentaiko along with the olive oil. Season with a little ground pepper, a squirt of yuzu or lemon juice and stir to combine.
When the pasta is done pour off a cupful of the cooking water and put it to one side, before draining the pasta. Return the pasta to the hot pot and add a little olive oil and a tablespoon or two of the hot cooking water, stirring all the time. You don't want to drown the pasta and make a soup, but rather add enough liquid to keep the strands supple and silky. Err on the side of less rather than more. Add the mentaiko mixture and toss everything together, adding a little more cooking liquid if the pasta looks too dry.
Serve immediately in shallow bowls with shredded shiso leaves scattered over and a few more grinds of white pepper.