2 While pasta is cooking, warm the vegetable oil in a large saucepan over medium-low heat.
3 . Add the onion, zucchini and garlic. Pour in tomatoes and sprinkle with Italian seasoning and red pepper flakes.
4 Cover the pan and cook until the vegetables are very soft, about 10 minutes. Season with salt and pepper.
5 Preheat oven to 325-o F. Blend together the egg whites and ricotta cheese until smooth.
6 In a 3-quart casserole dish, layer the pasta, ricotta cheese and tomato mixture, ending with a layer of the tomato mixture.
7 Sprinkle the top with grated mozzarella and Parmesan cheese.
8 Bake until golden brown on top and bubbling, about 45 minutes.
Source: National Pasta Association