Place frozen dish in fridge to thaw overnight.
Preheat oven to 375°F.
Remove lid and parchment. Generously oil one side of a piece of foil and cover the dish. Place the dish into the oven and bake for 60 minutes.
Gently remove foil (be careful not to pull o the cheese as you remove the foil. Bake another 20-30 minutes or until heated through and the internal temperature reaches 165°F.
Top with chopped onions and cilantro. Serve with sour cream and fresh Avocado Salsa.