01 - Heat olive oil in a large skillet over medium heat. Add chopped onion and cook until translucent, about 2–3 minutes. Stir in garlic and cook for 30 seconds.
02 - Add ground beef to the skillet. Cook, breaking it up with a spoon, until browned, approximately 5–7 minutes. Drain excess fat if necessary.
03 - Incorporate cumin, chili powder, smoked paprika, oregano, salt, and black pepper into the beef. Cook for 1 minute to toast the spices.
04 - Add refried beans, tomato sauce, and optional corn to the skillet. Stir to blend ingredients and simmer for 5 minutes until heated through.
05 - Heat flour tortillas in a dry skillet or microwave until soft and pliable.
06 - Place each tortilla flat and spoon one-quarter of the beef and bean mixture down the center. Top with shredded cheddar and Monterey Jack cheeses.
07 - Layer shredded lettuce, diced tomato, a dollop of sour cream, and optional cilantro atop the cheese.
08 - Fold the sides of the tortilla and roll up tightly to enclose the filling.
09 - Serve immediately or for a crisp texture, grill the burrito seam-side down in a hot skillet for 1–2 minutes per side.