Preheat the oven to 350 degrees F.
In a large skillet, brown the ground beef with the onion, green bell pepper and garlic over medium heat.
Drain the excess grease.
Reduce the temperature to low and stir in the refried beans, taco sauce and black pepper. Cook for 4-6 minutes until all ingredients are thoroughly combined and heat through.
Stir in 1 cup of cheddar cheese and allow it to melt.
Remove the pan from the heat.
Assemble the chimichangas.
Lay the tortillas on a working surface.
Spoon the meat mixture onto the tortillas. Approximately 1/3 cup of the meat mixture.
Fold in both ends of the tortilla and roll tightly.
Place on a baking sheet with the seam on the bottom of the pan.
Brush the tops with the melted butter.
Bake at 350 degrees F for 12-15 minutes until golden brown and crispy.
Serve topped with the lettuce, remaining cheese, sour cream, olive and tomatoes.