We had a party Monday night and ordered Sushi for 20 people - about 25 percent of the Sushi went uneaten, mostly plain rolls like tuna and yellow tail. I would hate to throw out 10+ rolls - any suggestions?
As hobodave points out, you'll need to cook the fish, because the leftovers won't be safe to eat raw. While deep frying sounds tasty, I'd be concerned that the cooking time would be too short to kill much bacteria. Perhaps you could layer them in a casserole dish, maybe throw some more rice, sesame seeds, sauce(s) on top, and bake until browned as an asian casserole of sorts.
Be smart, though, and if they've been out of the fridge for a long time, or if they smell strongly, just toss 'em.
First a red flag on the raw fish here. That said, some shops keep the sushi refrigerated for a couple of days before selling it. It's not what I prefer, but it is still edible. If you kept it out on a buffet for a couple of hours then I'd say you're going to have to say goodbye to the rolls.
If you're willing to take them apart you could go for a stir fry solution. Let's say a fishy variation on this recipe.
Before proceeding, consider carefully where the rolls have been and use your nose.