1. Brown Hamburger.
2. In a saucepan combine tomato sauce, beef gravy, and 1 package of taco seasoning. Heat until warm.
3. Spray bottom of 9 X 13 pan with cooking spray. Put six soft taco shells in the bottom of pan spread out to cover bottom of pan, break if you have to.
4. Spread refried beans on top of those. Spread tomato sauce mixture on top of the beans, sprinkle hamburger on top of sauce, sprinkle cheese on top of hamburger.
5. Put another six soft taco shells on top of that layer.
6. Repeat steps above (you can do another layer if you wish, but you will need more soft taco shells).
7. Reserve cheese for top layer, cover and bake at 375 for 45 minutes.
8. Sprinkle with cheese, bake uncovered until cheese is melted, 10 minutes. Let cool 5 minutes and cut into sqaures. Garnish with salsa, lettuce, sour cream if desired.