Preheat oven to 400°. In a large skillet, cook beef, bacon and onion over medium heat until meat is no longer pink, breaking it into crumbles; drain. Add cheese; cook and stir until melted. Remove from heat., Flatten biscuits into 5-in. circles; top each with 1/3 cup beef mixture. Fold sides and end over filling, and roll up. Place seam side down on a greased baking sheet. If desired, brush with egg and sprinkle with sesame seeds., Bake until golden brown, 18-20 minutes. In a small bowl, combine ketchup and mustard; serve with roll-ups.