8 (6-inch) corn tortillas
1 tablespoon olive oil
½ cup onion; chopped
1-1/4 lbs. Ground beef
1-1/4 tsp Chili powder
Kosher salt to taste
Black pepper to taste
2 (16 oz.) jars enchilada sauce
1-3/4 cups shredded cheddar cheese
1-3/4 cups shredded Monterey jack cheese
Preheat oven to 375 degrees. Wrap tortillas in foil and keep in oven for 10 minutes.
Heat oil in a large saucepan over medium heat. Add onion and cook until soft and translucent, about 4 minutes. Increase heat to medium-high, add ground beef and cook, stirring occasionally, until thoroughly browned, about 5 minutes. Stir in chili powder, season with salt and pepper taste. Transfer beef to colander to drain.
Pour 1 jar of enchilada sauce into a 9 x 13 inch baking dish. Spoon about 1/3 cup ground beef and 5 tablespoons mixed cheeses inside each warm tortilla, roll up in cigar fashion and place enchiladas seam side down next to each other in baking dish. Cover evenly with second jar of enchilada sauce and remaining cheese. Bake in 375 degree oven until bubbling, about 15 minutes.