In a Large Nonstick Skillet, brown up Ground Beef on med/ high heat.
Drain.Reduce heat. Add in onion.Saute' until translucent.
Heat oven to 350.
In a glass,4 cup Pyrex,pour Enchilada Sauce & Tomato Sauce. Stir to combined. Set aside. Ladel a little sauce to coat bottom of greased 13 x 9 baking dish.
Place tortilla on a work surface. Spoon 1/4 to 1/3 cup of the meat mixture down the middle. Sprinkle 2 Tablespoons of cheese on top of the meat. Drizzle 1 Tablespoon of sauce on top. Wrap the tortilla around the filling tightly and place it seam-side-down in the baking dish. Repeat with remaining tortillas and filling until you have finished filling 10 tortillas. Place the tortillas side-by-side in the pan- it's okay if they are all snuggled in there tightly.
Pour remaining enchilada sauce over the top of the stuffed enchiladas. Cover the dish with foil and bake for 30 minutes.
Remove pan from the oven and take off the foil. Sprinkle remaining cheese on top; return to the oven and let the cheese melt (about 5 minutes).