Onigiri is simple, but still good. Also good toasted
For this you'll need:
Short grain rice
Some filling (fish, umeboshi, other tsukemono, etc.)
Make rice according to the directions on its package. Cut the top off of a zipper bag and place the bag in a 1/2 cup measuring cup. Cut sheet of nori into strips. When rice is done and still hot, place a bit in the bag, let it steam up the plastic, and dump it out. Sprinkle salt on the plastic and then fill the cup completely with rice. Bury a piece of filling in the middle and remove the plastic bag from the cup. Form into a ball or triangle and remove from the plastic. Wrap a strip of nori around the bottom.
You can make them bigger if you'd like. I just think small ones are cute.