Red Bell Pepper rinsed; trimmed and cut into bite-size pieces
Freshly ground black pepper to taste
Shredded Sharp Cheddar Cheese
Shredded Gruyere Cheese
Preheat oven to 350º F. Coat a 3 i/2 quart casserole dish or a 9 x 13-inch casserole dish with nonstick cooking spray.
Bring a pot of salted water to a boil. Add pasta and cook for about 8 minutes. Add broccoli florets, frozen peas, red peppers and cook for an additional 2 to 3 minutes. Drain, rinse well with cold water and drain again. Pour into prepared casserole dish.
Meanwhile, in a large sauce pan set over Medium heat, melt the butter. Add flour to the pan and whisk until smooth and bubbly. Slowly whisk in milk. Add cayenne pepper, dry mustard, nutmeg, and season to taste with salt and pepper. Stir constantly until sauce begins to boil, about 8 to 10 minutes. Remove from heat source.
Stir the Cheddar and Gruyere cheese into the hot sauce and continue stirring until cheese melts and consistency is smooth and thick.
Stir sauce into pasta and vegetable mixture. Sprinkle Parmesan cheese over the top. Bake for 30 to 35 minutes, or until the top is golden and the sauce is bubbly. Cool for several minutes before serving.