Start by making your homemade enchilada sauce. In a saucepan, heat some oil over medium heat, then add chili powder, garlic powder, and cumin. Stir for about 30 seconds, then add tomato sauce and simmer for 10 minutes. Season with salt and pepper to taste.
In a large skillet, heat 3 tablespoons of vegetable or canola oil over medium-high heat. Add the ground beef, breaking it apart with a wooden spoon. Cook until browned and cooked through, about 7-10 minutes. Drain excess fat if necessary.
In a mixing bowl, combine the cooked ground beef with 1/2 cup of the enchilada sauce and 1/2 of the grated cheese. Mix until well combined.
Preheat your oven to 350°F (175°C). Take a tortilla and spread a small amount of enchilada sauce on it. Spoon a portion of the beef mixture onto the tortilla, roll it up, and place it seam-side down in a baking dish. Repeat with the remaining tortillas.
Once all the enchiladas are in the baking dish, pour the remaining enchilada sauce over them, ensuring they are well covered. Sprinkle the remaining grated Monterey Jack cheese on top.
Cover the baking dish with foil and bake in the preheated oven for 20 minutes. Remove the foil and bake for an additional 10-15 minutes, or until the cheese is bubbly and golden.
Once baked, remove the enchiladas from the oven and let them cool for a few minutes. Serve with a dollop of sour cream and a sprinkle of fresh cilantro if desired. Enjoy your homemade Beef Enchiladas!