Here's what I often use for sushi:
cucumber, carrot, scallion, lettuce, blanched spinach (oshitashe), avocado, kanpyo (pickled gourd), pickled burdock root, oshinko (pickled daikon--the bright yellow stuff), marinated shiitake mushrooms, radish sprouts, pickled grated radish, sliced mango, steamed asparagus, tofu (either cold, smoked, marinated, or fried--abure age cut into strips), miso, pickled plum, sliced cooked lotus root, bamboo shoots, red bell pepper, cabbage, shiso leaf, steamed mustard greens, steamed or fried sweet potato or pumpkin, steamed string beans, sesame seeds (brown or black toasted).
I make inari (fried tofu pockets stuffed with rice) with abure age. A lot of these ingredients come from asian markets in Cambridge, but many are available at whole foods.
To make the sashimi style sushi that looks like sliced salmon, I steam baby carrots and slice them thinly lengthwise, then layer them on top.
I also like making vegetarian tempura sushi (battered fried vegetables, like green beans, eggplant, squash, carrot)
The kids also LOVE onigiri sushi (rice balls, but we often do rice triangles, plain, seasoned, stuffed, rolled in sesame seeds, etc.). You can add just about anything to them. One of my favourites in Japan are onigiri with pink beans (cowpeas)--they taste quite sweet with the mirin added to the rice.
milk donation : mother to Ryan (6), AJ (5), Nate (2), Maia (1) all born at home, I have a kid-friendly food & bento blog, : :