Place half of the oregano and garlic in the olive oil. Allow to steep for 24 hours to infuse the oil.
Flatten the dough, and cut into 4 circles. Using a fork, dock the dough, and let it rest overnight in the refrigerator.
Preheat oven to 400 degrees F.
Remove dough from refrigerator, brush with a thin layer of mustard, and sprinkle the remaining oregano. Cut the tomatoes in thin slices, and place them in a nice circular pattern. Add the olives, drizzle infused oil and the fleur de sel.
Place tart on a cookie sheet and bake for 10 to 15 minutes in a 400 degree F oven.
To serve: Serve immediately after coming out of oven. Decorate with basil leaves and a drizzle of infused olive oil.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.