Preparation

1. Preheat the oven to 350 degrees.
2. Grease a 9-inch square baking dish.
3. Cook the macaroni in boiling water until barely tender; drain.
4. Combine the macaroni, zucchini, broccoli, bell pepper, and spinach in a large bowl.
5. Melt the butter in a heavy saucepan over medium heat. Add the flour and cook, whisking constantly, for one minute.
6. Add the milk a little at a time, whisking vigorously to prevent lumps from forming.
7. Add the mustard and continue to cook, stirring constantly, until the mixture thickens and begins to simmer.
8. Simmer for one minute.
9. Remove from heat and add the cheese all at once, stirring until smooth.
10. Season to taste with Tabasco, salt, and pepper.
11. Pour the cheese sauce over the macaroni and vegetables and stir to coat.
12. Spread the mixture in prepared pan, cover with crumb topping and bake for 45 to 60 minutes, until nicely browned and bubbly in the center.