In a large bowl combine egg white and bread crumbs. (If using veal or beef, stir in 2 tablespoons water.)
Stir in carrot, onion, green pepper, salt, and pepper.
Add Parmesan cheese and ground meat; mix well.
Shape meat mixture into four % inch thick patties.
Spray a cold grill rack with nonstick spray coating.
Then, place rack on grill- Grill burgers on an uncovered grill directly over medium coals for 7 minutes.
Turn and grill 8 to 11 minutes more or till no pink remains.
Place 1 tomato slice atop each burger and grill 1 minute more.