If you have access to a Korean supermarket but not a Japanese one, myeongran jeot (often labeled pollack roe) will provide a close substitute, as will perilla leaves for the shiso. Both Korean and Japanese pollack roe can get pricy, but you only need a small amount for the pasta — I picked up a 2 oz package for around $3.

If you want a creamier, more alfredo-like pasta, use 2 tbsp cream and 2 tbsp milk to thin the pasta after adding the roe and butter. You may still want to thin it with a bit of pasta water, as necessary.

Lastly, I served this with some blistered shishitos — all I did for them was heat a cast-iron skillet over high heat, add the shishitos and let them cook until charred, then toss them with a bit of olive oil and coarse salt.