Heat olive oil in a pan over medium heat. Add onions and bell pepper, sauté for 3-4 mins until softened.
Add the minced beef and cook, breaking it up with a spoon, until browned (5-6 mins). Drain excess fat if needed.
Add cumin and garlic powder. Stir for 30 seconds until fragrant.
Add a splash of water if dry. Finally, season with salt and pepper.
Place a tortilla on your saucepan (you don't even need to wash it).
Pile a layer of cheese on half of the tortilla.
Spread a generous amount of the beef mixture on top of the cheese, then fold the other half over to form a half-circle.
Turn on heat and cook for 2-3 mins over medium heat per side, or until golden and crispy and the cheese is melted.
Serve with salsa and guacamole on the side.