01 - Preheat oven to 400°F. Line baking sheet with parchment paper.
02 - In skillet over medium heat, cook chopped bacon until crisp. Remove and set aside, leaving a little bacon fat in pan.
03 - Add onion to skillet and sauté 2-3 minutes until softened. Add garlic and cook 30 seconds more.
04 - Add ground beef, salt, and pepper. Cook until browned and crumbly, breaking up with spatula. Drain excess fat.
05 - Stir in ketchup, mustard, and cooked bacon. Remove from heat and cool 5 minutes.
06 - Unroll puff pastry on lightly floured surface. Spread beef mixture evenly over pastry, leaving ½ inch border on all sides. Sprinkle cheddar on top.
07 - Starting from one long side, roll pastry tightly into log. Pinch seam to seal.
08 - Slice roll into 16 even pieces. Place each slice, cut side up, on prepared baking sheet.
09 - Beat egg with 1 tbsp water. Brush tops of rollups with egg wash.
10 - Bake 18-22 minutes until puffed and golden brown. Cool a few minutes before serving.