Seafood Enchiladas

Preheat the oven to 350 degrees F (175 degrees C).

Make the filling: Melt butter in a large skillet over medium heat. Add onion and sauté until translucent, about 5 minutes. Remove from the heat. Stir crabmeat, shrimp, and 1/2 of the Colby cheese into the skillet.

Arrange a large spoonful of filling across the center of each tortilla, then roll tortillas around filling. Place enchiladas, seam-side down, into a 9x13-inch baking dish.

Make the sauce: Heat half-and-half, sour cream, melted butter, parsley, and garlic salt in a saucepan over medium-low heat, stirring often, until lukewarm and well blended. Pour over enchiladas, then sprinkle remaining cheese over top.

Bake in the preheated oven until crab and shrimp are cooked and cheese is melted, about 30 minutes.