Preheat oven to 400°. Spray 13 x 9-inch baking dish with no-stick cooking spray; set aside.
Prepare Knorr® Leek recipe mix according to directions in large saucepan. Reduce heat to low, then stir in red pepper, cheddar cheese, Swiss cheese and 1/4 cup Parmesan cheese. Stir until cheeses are melted. Stir in vegetables and macaroni. Turn into prepared baking dish, then sprinkle with remaining 1/4 cup Parmesan cheese.