Growing up, my favorite fish dish was tara (black cod) kasuzuke. We used to have a fishman that would drive out to our area, and I used to enjoy looking at the different types of seafood he had inside his truck (as well as the bugs crushed against his truck grill). But the only thing I ever wanted to get from him was tara kasuzuke (and maybe ikura).
You can buy tara kasuzuke ready-made from almost any Japanese market nowadays, but it's easy enough to make your own, so I thought I'd try it. The main ingredient aside from the fish, is the sake lees. Sake lees are the leftover dead yeast from sake production. Along with some sugar and mirin, it aids in the marination process of the fish.
I should have let the fish marinate another day at least, since the flavor was too light. However the nasu (eggplant) shigiyaki was strong, so it evened out in the end. The bag of sake lees was really big, so I'll probably be making kasuzuke again soon.