Preheat oven to 400°F.

Add ground beef and chopped onion to a skillet over medium heat. Break up the beef and cook until browned and the onion has softened. Drain excess grease if necessary.

Add taco seasoning and stir. Cook for another couple of minutes.

Add 1 cup enchilada sauce and 1 cup refried beans. Stir together and simmer over medium to medium-low heat for about 5 minutes.

Melt the butter and brush the bottom of a 9x13-inch baking dish with some of the melted butter.

Add Colby Jack cheese down the center of each flour tortilla. Top with beef filling and a little more cheese.

Fold in the sides, roll tightly, and place seam-side down in the prepared baking dish.

Brush the tops of the enchiladas with the remaining melted butter.

Bake uncovered at 400°F for about 10 minutes, or until the tortillas are beginning to turn lightly golden.

Remove from the oven. Pour the remaining enchilada sauce over the tortillas and top generously with the remaining Colby Jack cheese.

Cover tightly with foil and lower the oven temperature to 350°F.

Return to the oven and bake covered for about 20 minutes, until hot, bubbly, and melted.

Serve with white rice and the remaining refried beans. Spoon the cheesy enchilada sauce from the bottom of the baking dish over everything before serving.