In a medium skillet, heat a drizzle of oil over medium heat. Add the lean ground beef and diced onion, cooking for 5-7 minutes until the beef is browned and the onions are translucent. Stir in minced garlic, cumin, and chili powder, sautéing for an additional minute until fragrant.

Before assembling the enchiladas, warm your tortillas to prevent tearing. Wrap the tortillas in a damp paper towel and microwave for about 20 seconds.

On a clean surface, lay out each tortilla and spoon a generous portion of the beef mixture onto the center. Tightly roll each tortilla, placing them seam-side down in a greased baking dish.

Pour the enchilada sauce evenly over the assembled tortillas, then sprinkle a generous layer of Monterey Jack cheese on top.

Preheat your oven to 375°F (190°C). Place the baking dish in the oven and bake the enchiladas uncovered for 20-25 minutes.