Chicken, Spinach, and Caramelized Onion Casserole

Preheat oven to 350°F. Spray a 9"x9" baking dish with cooking spray, or grease with butter or oil.

Cook pasta according to package instructions. Once done, drain and add to baking dish.

Add olive oil to a large skillet over high heat, and add chicken once oil is shimmering. Season with salt, pepper, and garlic powder. Saute until chicken is cooked, then move to baking dish.

Reduce skillet heat to medium-low, and add butter and sliced onions. Season with salt and pepper, and cook down until onions are caramelized and jammy, stirring every 5 mins.

Add spinach to the skillet and cook until wilted. Add mixture to chicken in the baking dish and mix together.

In a small saucepan, heat butter over medium-low heat. Once melted, stir in flour and cook for 2 mins. Slowly stream in milk, whisking constantly, until mixture is smooth and no lumps remain. Bring to a boil, then reduce heat and simmer until sauce is thickened.

Turn off the heat on the sauce, then add garlic powder, salt, lots of pepper, and white pepper and onion soup to sauce and whisk until fully combined. Pour over mixture in baking dish.

Melt butter for the topping, and mix with bread crumbs, salt, and pepper. Spread evenly over top of mixture in baking dish.

Bake for 25 mins or until bread crumb mixture on top is golden brown,