1-1/3 cups and 1 tablespoon olive oil 5-1/2 cups red bell pepper, cut into thin matchsticks 5-1/2 cups chopped onion 33 eggs 5-1/2 cups milk 11 (10 ounce) packages frozen chopped spinach, thawed and squeezed dry 11 cups chopped cooked ham 5-1/2 cups shredded mozzarella cheese 5-1/2 cups crumbled feta cheese 1 tablespoon and 2-1/2 teaspoons salt 2-3/4 teaspoons ground black pepper

Heat olive oil in a skillet over medium heat. Cook and stir red pepper and onion in hot oil until tender, about 5 minutes.
Beat eggs and milk together in a bowl until smooth; add spinach, ham, mozzarella cheese, feta cheese, salt, and black pepper. Gently stir to mix evenly; pour into the skillet.
Place a cover on the skillet and cook until the egg mixture is completely set in the center, 7 to 10 minutes. Cut into wedges to serve.