Preheat grill (indoor or outdoor).
Finely dice 1/4 of an onion and 1/2 of one bell pepper; mince garlic. Slice remaining 1/2 and whole, bell peppers into strips, slice tomato and cheese, and cut carrots and celery into sticks.
Stir together chili powder, oregano, paprika, cumin, salt, and pepper.
Thoroughly mix spices, diced veggies, and garlic into beef; shape into 4 burgers and place onto hot grill. Cook until no longer pink and juices run clear.
Place each burger on a bun and top with salsa, lettuce, tomato, and cheese as desired.
Serve with carrot, celery and pepper sticks, and apple slices on the side.