Preheat the oven to 325 degrees F.
Spray a 2 quart baking dish with vegetable cooking spray, set aside.
Bring a large pot of salted water to a boil and cook the macaroni until just tender, about 8 minutes. Drain, rinse under cold running water, and return to the pot.
Meanwhile, heat the wine in a large nonstick skillet over medium-high heat. Add the bell peppers, squash, onions, and garlic, and 2 teaspoons of salt, and cook until tender, 10 to 12 minutes, adding a little water if more liquid is needed. Drain the vegetables in a large colander set over a bowl. Add the vegetables to the pasta and set the juices from the vegetables aside.
Melt the butter in a small saucepan over medium heat. Add the flour and mustard and cook, stirring constantly, for 2 to 3 minutes. Whisking constantly, slowly pour in the milk and the juices from the vegetables. Add the thyme and the remaining 1 teaspoon of salt. Cook, stirring, for 4 to 5 minutes. Season with additional salt and pepper, to taste.
Beat the ricotta until smooth and slowly beat in the white sauce. Toss with the macaroni mixture. Transfer to the 2-quart baking dish and sprinkle with Parmesan. Sprinkle bread crumbs over the top and lightly spray them with the vegetable cooking spray. Bake until top is golden brown, about 35 minutes. Serve immediately.
Copyright 2002, Janette Barber and Christina Deyo, all rights reserved