Add just enough sauce to the casserole dish to thinly coat the bottom.
Add a ¼ cup of each Monterrey Jack and Cheddar to the beef mixture and stir to evenly distribute.
Dampen two paper towels and wrap half of the tortillas in the towels. Repeat additional paper towels and the remaining tortillas. Heat in a microwave for thirty seconds to 1 minute, until warmed and pliable.
One at a time, add 2 tbsp of beef filling to a tortilla and roll tightly. Place seam-side down in the dish. Continue to roll enchiladas, placing them side-by-side until you can no longer fit any more in the dish.
Pour the remaining sauce evenly over the enchiladas and sprinkle with remaining cheese.
Bake, covered with aluminum foil for 20 minutes. Remove the foil and bake for an additional 15 minutes, uncovered. Allow to cool, serve and enjoy