This recipe comes from my sister, Lori, in NY! It's so easy and soooo yummy! Enjoy!!
Saute in olive oil until crisp-tender: 1 small to medium yellow onion, chopped; 3-4 full-size (or more if using baby carrots) carrots, chopped; 1 green pepper, chopped; 1 red pepper, chopped; 3-4 cloves crushed garlic and 2 teaspoons Italian Seasoning ( I usually add mushrooms if I am making a vegetarian version of this). To this, add a BIG jar of your favorite spaghetti sauce (I usually add the tomato & basil version) and warm. I usually add A LOT of sauce b/c I find that ziti has a tendency to dry out, so don't skimp on this step!! If I was adding hamburger, I would fry it separately and add it with the sauce.
Meanwhile, cook and drain a box of Ziti and pour into a large casserole dish. Pour the sauce mixture on the ziti and mix together. Using a large bag of shredded mozarella cheese, mix it with the sauce and sprinkle the rest on top. Add freshly grated parmesan cheese to the top and bake, uncovered, at 350 degrees until bubbly and the cheese is melted and slightly browned (approximately 30 -45 minutes).