Preheat oven to 375°. Then Boil the rotini, cook for a minute less than al-dente. Prepare the rest of the casserole as the pasta cooks.
Season the cubed chicken with ½ tsp Italian seasoning, ¼ tsp pepper and ⅓ tsp garlic salt.
Heat 1 tbsp olive oil in a skillet over medium-high-heat. Add the chicken and sear, tossing occasionally, for 4 minutes.
Add the broccoli and cook for 3-5 minutes. Remove from heat.
In a small-bowl, mix the cream of mushroom soup, milk, 2cups sharp-cheddar-cheese and sour cream. Then add the cooked broccoli and chicken.
Drain the pasta and mix it with all the casserole ingredients.
Lightly grease a 9x13" casserole-dish then put in the casserole filling. Top with 1 cup regular cheddar-cheese. Cover and bake for 20 minutes.
Lightly grease a 9x13" casserole-dish then put in the casserole filling. Top with 1 cup regular cheddar-cheese. Cover and bake for 20 minutes.
Remove the cover and top with crispy-fried-onions and bake for 8 minutes.
Serve and enjoy!