Preheat the grill or oven to 375°F and lightly grease an 8x8 casserole dish.
In a mixing bowl, combine all ingredients except the shredded cheeses, mixing until well incorporated.
Pour the mixture into the prepared dish and evenly sprinkle the cheeses over the top.
Bake for about 30 minutes, or until the cheese is melted, bubbly, and lightly golden.
Serve warm with your favorite chips.