Heat a large pot or skillet and add oil. Season meat with salt and pepper. Brown the meat cubes 1-2 minutes on each side. Place meat in the slow cooker with chopped onions.
Strain the onions from the sauce and add them to the shredded beef. Set the remaining sauce aside.
Preheat oven to 400 degrees.
Lay a tortilla out on a flat surface. Add ¼ cup refried beans, ½ cup shredded beef, 2-3 tablespoon cheese. Fold the side of the tortilla in and roll. Repeat. Place the burrito seam side down in a 9x13 baking dish. Pour the strained sauce over the top and add the rest of the cheese.
Baked for 25 minutes.
Serve with your favorite toppings
Video
Notes
If you don't like spicy you can substitute tomato paste for the chipotle or just leave it out altogether.Place the rest of the chipotle pepper in adobo sauce in a ziplock freezer bag and freeze for later.This makes 8 large burritos. You can easily adjust the size.