Cook the bacon first in a medium sized saute pan over medium heat until crispy. Let drain on a paper towel, reserving bacon fat in pan.
Place onions into bacon fat, season with salt and pepper, cook on medium low heat until soft and a deep brown color, stirring often. About 45-50 minutes. Set aside.
Preheat oven to 450 degrees. Take out puff pastry and handle per the instructions on the back of the packaging. Cut out circles with a cookie cutter in 15 pieces. Place on a sheet tray lined with parchment paper. Make sure they are not touching.
Whisk egg with the water and brush the top of the pastry rounds. Top evenly with the caramelized onions and bacon. Evenly sprinkle with the herbs, and top with 1/2 teaspoons grated cheese on each.
Bake with 16 -20 minutes until golden brown. Serve and enjoy!