Faux Unagi - Herring Kabayaki Style

Eel (unagi) is a very popular fish, both for sushi and as a street snack, usually grilled and basted in a lovely sticky kabayaki sauce. Unfortunately, the European eel population is on the brink of collapse due to overfishing of glass eels to supply the eel farms in the Far East. Until the eel population stabilizes, I like to play around with alternatives. In this recipe I use herring, which are similar to eels, with a fatty, meaty texture, albeit they are a sea fish whereas the eel spends