Remove from food processor and dust with flour. On a floured surface roll out into a 12" circle. Fit into a 10" tart pan. Poke bottom with a fork, cover and place in the freezer for 1 hour.
Preheat oven to 350°F.
Blind bake for 10 minutes. Remove from oven and immediately brush the bottom and sides with egg wash while hot. This will seal the tart shell.
In a skillet heat olive oil on medium and sauté the onion slices until soft and translucent. Sprinkle with herbes de Provence and salt. Set aside to cool.
Place the brown sugar, pepper and nutmeg in a small bowl. Microwave the diced bacon until just about crispy. Discard the grease and place the bacon in a small skillet on medium heat then add the brown sugar mixture. Stir until the sugars dissolves into the bacon. Set aside and allow to cool.
Bake for about 30 minutes, or until the potatoes are soft when tested with a toothpick. Tip: When the potatoes are soft turn on the broiler and watch carefully to brown the cheese on top then serve.