Preheat oven to 350°F.
Cook the chicken if not already cooked and dice into bite sized pieces. Place in a large bowl.
2 boneless, skinless chicken breasts, cooked and diced into small pieces
Bring a large pot of water to boil and cook pasta according to package directions. During the last 3 minutes, add the broccoli in with the pasta. Drain and rinse the pasta and broccoli with cold water to stop the cooking process. Pour into large bowl with the chicken.
1 lb. pasta (Mezzi Rigatoni, penne, rotini, etc.), 3 cups broccoli, chopped into small pieces (about 2 small heads of broccoli)
Make the Alfredo sauce: Place a large saucepan on the stove over medium heat and melt the butter. Whisk in the flour and continue to whisk the roux for 1-2 minutes
1/4 cup butter, 1/4 cup flour
Slowly whisk the milk in increments. Repeat until all milk has been added. Add in the Parmesan cheese, garlic, salt, pepper and Italian seasoning. Simmer for 2-3 minutes, stirring occasionally. Sauce will appear thin, but will thicken as it bakes.
4 cups whole milk, 3/4 cup Parmesan cheese, freshly grated, 1 1/2 tsp. salt, 1/2 tsp. pepper, 1 tsp. garlic, minced, 1 tsp. Italian seasoning
Pour the sauce over the pasta, broccoli and chicken and pour into your casserole dish/baking dish. Mix until combined and pasta is coated evenly.
Top the pasta with mozzarella cheese and bake for 20-25 minutes or until the cheese is melted and barely begins to brown.
1 1/2 cup mozzarella cheese, freshly shredded
Remove from oven and serve warm. Garnish with parsley or red pepper chili flakes, if desired!