Simmered Sea Bream Roe

In early spring in Japan, simmered sea bream roe, which is cooked in a broth of sake (rice wine), mirin (sweet cooking wine), and dashi (fish stock) with some fresh ginger slices, appears at every dining table, both at home and in restaurants. I could never find sea bream roe in New York, but one day in early summer, I encountered some beautiful fish roe at a nearby fishmonger. I was told that it was from shad, a fish I had never heard of, and that it was a seasonal del