Method
Preheat oven to 350°F. Coat a 9x13 pan with nonstick spray.
Place broccoli in a strainer to thaw.
Mix sour cream, seasonings, garlic, and stock in a bowl until fully combined.
Fold in chicken, veggies and 1⁄2 of the cheeses. Mix until combined. Spread evenly in the pan.
Top with remaining cheeses and French fried onions.
Cover tightly with foil and bake for 30 minutes.
Uncover and bake for 15 minutes. Remove from oven and let rest for 10 minutes before serving.