Mix beef, bread crumbs, egg, water and seasonings together. Shape into about 16 meatballs.
Place equal amounts of meatballs, zucchini, onions, and peppers in center of 4 tinfoil sheets. Pour about a half cup of sauce over each.
Fold short edges of foil over loosely to allow heat to circulate. Now fold other two edges in and seal shut.
Put meatball packets on a grill over hot ash covered coals. Allow to cook about 20 to 30 minutes, or until meatballs are no longer pink in centers and veggies are tender. Be sure to turn the packets once.
When finished unwrap packets, sprinkle with grated cheeses and either serve in the foil "bowls with bread or breadsticks to dip in sauce, or spoon out onto rolls and serve as a sandwich.