Preheat oven to 325 degrees. Mix taco seasoning into raw ground meat before cooking it.I find this makes the meat taste more flavorful than sprinkling on after cooking.
Brown ground meat until fully cooked on medium heat.After cooked, add water and simmer 3 minutes on low until some of the water is cooked off but not all of it.
While meat is cooking, microwave or cook frozen spinach until just warm. Squeeze out most of the liquid.Too much liquid in the meat or spinach makes for soggy tortillas. Too little makes it a bit dry.
Spray casserole with cooking spray.First layer 3 tortillas to cover bottom of pan. May overlap slightly.If your size tortilla doesn't fit, just tear them in half to make fit your oval casserole or 9x13 pan.
Divide your meat and cooked spinach for 3 layers.On top of tortillas, spread meat then spinach. Continue for 2 more layers. End with tortillas.
Cover casserole with lid or foil. Bake 325 for 45 minutes until hot.Top with shredded mozzarella and bake 5 more minutes until cheese is melted and lightly browned.
You may make this recipe to serve 4 by using an 8x8 casserole, 1 lb meat, 1 package taco seasoning, 6 tortillas, 1 box spinach, 1/2 cup water and 1 cup cheese.Still takes about 30-40 minutes to heat through in oven.
I serve with shredded lettuce,salsa and sour cream.You may add sliced black olives to your layering.May use shredded leftover cooked chicken-very versatile recipe.