1 1/2 lb. ground beef
1 1/4 tsp. salt, divided
1/4 tsp. pepper
2/3 c. shredded zucchini
1/3 c. thinly sliced mushrooms
1/4 c. chopped red pepper
1/2 tsp. Italian seasoning
2 tbsp. each olive oil and grated Parmesan cheese
4 whole wheat hamburger buns, split
4 tsp. butter

Sprinkle 1 teaspoon salt and pepper over ground beef; mix lightly but thoroughly. Divide meat into 8 equal portions and form into patties.

Cook zucchini, mushrooms, red pepper, Italian seasonings, and remaining salt in oil in large frying pan over medium heat 3-4 minutes, stirring occasionally. Cool; stir in cheese. Place an equal amount of vegetable mixture in center of 4 patties. Top with remaining patties. Press edges together securely to seal. Broil over medium coals 5-6 minutes. Turn and continue broiling 5-6 minutes or doneness desired. Meanwhile spread cut sides of each bun with an equal amount of butter and toast on grill 1 minute. Place each patty on bottom half of each bun. Cover with bun top.