I think life is too short to keep the frozen salmon in the fridge! :-) So I made a teriyaki salmon bento, which was so fast to cook, that I had too much idle time in the morning... Just be careful not to overcook the teriyaki sauce, because it may have a burnt taste. Also, optional lotus root slices will keep the fish tender and juicy for the time when you can finally devour every last bit of it ;-)
Tuna paste is ridiculously easy to prepare and makes a great no cooking bento, cutting the preparation time to less than 20 minutes, including rice cooking time! Now, that's what I would call cooking on the go! You can also use the tuna paste for a great tasting onigiri or sushi.