Brown beef, drain and add Taco seasoning as directed on package. While meat is simmering heat refried beans in microwave - I use low fat butter to thin them a little.
Spread beans on bottom of deep baking dish, top with beef, then cheese. Cover with foil and bake at 350 for 30 minutes until bubbly. Serve on warm tostados with sides so people can fix them as they like.