Preheat the oven to 350°F. Spray a deep 13x9-inch casserole dish with cooking spray. Set aside.
Cook the rice per the package instructions just until tender then drain and cool. This can be done in advance, if desired. Do not overcook.
In a medium size mixing bowl, whisk together the broccoli cheese soup, cream of celery soup, mayonnaise, evaporated milk, pimientos, butter, rotisserie chicken seasoning, garlic salt and lemon pepper.
Add the cooked rice, chopped chicken, 2 cups cheese, steamed broccoli and green onions. Stir until fully combined.
Pour into the prepared dish, then sprinkle with the remaining 1 cup of shredded cheese.
Bake for 35-45 minutes until heated through and bubbly around the edge.
Let stand for 5 minutes, then serve.
Notes
Chicken: You can use any cooked chicken in this recipe. Leftover roasted chicken, grilled chicken or poached chicken breasts. You could also use leftover Thanksgiving turkey or chicken thighs.
Canned Soup: I don't often cook with creamed soups, but in the case of this casserole it just works. You could use cream of chicken soup, cream of mushroom soup or cream of broccoli soup in place of broccoli cheese soup.
Broccoli: You can use frozen broccoli or fresh broccoli for this recipe.
Seasonings: Rotisserie chicken seasoning is readily available on the spice aisle of most grocery stores. You could easily adapt using a different chicken seasoning like Poultry Magic or similar.
Salt: In place of garlic salt you could use 1 teaspoon plain table salt and 1 teaspoon granulated garlic or garlic powder.
Rice: If you prefer to adapt this recipe using long grain white rice or chicken seasoned rice you can! You'll need around 4-5 cups of cooked rice. When making this change, you may need to increase the amount of evaporated milk to accommodate. See how to make Oven Baked Rice here.
Bread Crumbs: You could top this casserole with buttered breadcrumbs or crushed Ritz crackers for a crispy topping.