Heat oven to 400 degree F. Heat the oil in a large skillet over medium heat. Add the onion and garlic and cook them for 3 minutes, stirring often. Add the beef and use a wooden spoon or a spatula to break it up while it cooks, util it is no longer red, about 3 minutes. Stir in the salsa, chili powder, salt, and pepper. Cook the mixture over low heat, stirring occasionally, for 10 minutes.

Place the tortillas on a plate and cover them with damp paper towels. microwave them until warm and pliable, about 45 seconds. Top each tortilla with 1/4 cup of the beef mixture, spreading it to an inch from the edges. Sprinkle cheese evenly over the beef.

Roll up the tortillas and place them on a foil-lined baking sheet with the seam side down. Brush the taquitos lightly with vegetable oil, then bake them until the filling is heated through and the tortillas are lightly browned, about 8 to 12 minutes. Serve them hot with sour cream, salsa and/or guacamole.