Mix enchilada sauce and tomato sauce together; set aside.
Brown ground beef; drain.
Mix beef, refried beans and 4 tablespoons enchilada sauce mixture.
Spoon beef mixture into tortilla along with onions and cheddar cheese. Roll tortilla up and place seam side down in prepared pan. Repeat with all tortillas.
Pour remaining enchilada sauce on top of rolled tortilla shells. Sprinkle with remaining Cheddar Cheese. Bake for 20-30 minutes.