Mexican Lasagne

In a large skillet over medium high heat brown hamburger with the chopped onion and chili powder. When it is browned drain the grease. Drain and rinse beans. Add beans to skillet with hamburger and heat through, about 2 min..
In a rectangular casserole dish, spread just enough tomato sauce on the bottom to coat. Add a single layer of flour totillas. You may have to tear some into shapes that fit(since tortillas are round and your pan is square). Spoon half of the hamburger mixture on top and carefully spread to cover.
Add another single layer of flour tortillas. Spread this layer with tomato sauce and then sprinkle with cheese.
Repeat these layers. Bake in oven for 30-40 minutes, when dish is a little bubbly. Serves 4-6.