Preheat oven to 375° F.

Place the taco shells in a bag and pound to break them up into crunchy chips.

Brown meat in a skillet. Add chopped onions and sautee with the meat.

Drain the oil from the meat/onion mixture.

Add tomato sauce (may substitute spaghetti sauce) and taco seasoning to the meat mixture.

Grease the bottom and sides of a 2 quart casserole dish with olive oil.

Reserve 3/4 cup taco chips and spread the rest on the bottom of the casserole dish.

Layer 1/2 the spinach over the chips.

Reserve 1/3 of the meat mixture. Use the rest to cover the spinach.

Sprinkle 1/2 the shredded cheese over the meat mixture.

Layer the remaining spinach

Add refried beans to the reserved meat and mix.

Add the meat and bean mix and spread to cover the spinach.

Bake for 25 minutes.

Add remaining cheese and chips. Bake or broil until cheese is melted (~5 minutes).

Let stand for 15 minutes and serve.