In a large skillet, heat the olive oil over medium heat.

Add the chopped onion and garlic, and sauté until the onion becomes translucent, about 3–5 minutes.

Add the ground beef to the skillet, breaking it up with a spatula. Cook until the beef is browned and fully cooked, about 8–10 minutes. Drain any excess grease if necessary.

Stir in the taco seasoning and mix well. If desired, add salt and pepper to taste. Cook for an additional 2 minutes to allow the flavors to meld.

In a separate bowl, mix the refried beans with half of the cheddar and Monterey Jack cheese. This will help bind the filling together.

Lay out each flour tortilla on a clean surface. Spread a generous amount of the refried bean mixture onto the center of each tortilla.

Next, add a portion of the seasoned ground beef on top of the beans. Make sure each burrito is filled evenly.

Sprinkle the remaining cheeses over the beef in each tortilla, allowing for a melty finish when cooked.

Carefully fold in the sides of the tortilla and then roll it up from the bottom, ensuring the filling is secured inside. Repeat this process for each burrito.

Preheat your oven to 375°F (190°C). Place the rolled burritos seam-side down in a baking dish.

Cover the burritos with aluminum foil and bake for about 15 minutes. Remove the foil and continue baking for an additional 10 minutes until the tops are golden and bubbly.

Once baked, remove the burritos from the oven and let them cool for a few minutes. Serve with sour cream and salsa on the side, garnishing with fresh cilantro if desired.