When I make fish and steamed rice for dinner, I always make sure I have
rice and a couple of ounces of fish left over.

The next day I have the previous night's steamed rice, unrefrigerated,
with the left over fish. I add same Japanese shake (furikake), maybe
some snips of nori, or packaged thai fried onions (which inexplicably
never loose their crunch) if I have some. It's a great lunch.

I always add a little drizzle of soy sauce. The soy sauce I've been
using for a while is yamasa. I ran out and I used some kikkoman. I
really like the yamasa better; I'm surprised in the difference in taste.