Velvety Chicken, Broccoli & Cheddar Rotini Pasta

Ingredients

• 2-6-ounce pre-cooked grilled chicken breasts, sliced in strips
• Salt and black pepper to taste
• 5 tablespoons unsalted butter, divided
• 1 tablespoon prepared Dijon mustard
• 1 teaspoon Salt
• 1 cup frozen chopped onions
• 1 cup half and half cream
• 2 cups whole milk
• 1/4 cup sour cream
• 1 pound Rotini pasta
• 3 cups frozen broccoli florets, microwaved till lightly steamed
• 3 tablespoons all-purpose flour
• 2 cups pre-shredded mild yellow Cheddar