Preheat oven to 375 degrees Fahrenheit (190 degrees Celsius).
In a large skillet over medium-high heat, brown the ground beef and diced onions until the meat is fully cooked. Drain excess fat.
Stir in the taco seasoning and 0.25 cup of water, simmering for 5 minutes until thickened.
Warm the flour tortillas for 20 seconds in a microwave to increase pliability.
Spread 0.25 cup of refried beans onto the center of each tortilla, then top with a portion of the beef mixture.
Fold the sides of the tortilla inward and roll tightly; place seam-side down in a 9x13 inch baking dish.
Pour the red enchilada sauce evenly over the rolled burritos.
Sprinkle the shredded cheese over the sauce layer.
Bake for 15 to 20 minutes until the cheese is melted and the sauce is bubbling.
Top with sour cream, cilantro, and black olives before serving.