Zucchini Burgers

Ingredients (12)

• 2 cups shredded zucchini
• 1 medium onion, finely chopped
• 1/2 cup dry bread crumbs
• 2 large eggs, lightly beaten
• 1/8 teaspoon salt
• Dash cayenne pepper
• 3 hard-boiled large egg whites, chopped
• 2 tablespoons canola oil
• 4 whole wheat hamburger buns, split
• 4 lettuce leaves
• 4 slices tomato
• 4 slices onion