Makes 3 tarts.
Set a pizza steel in the upper third of the oven. Heat an oven to 500 F.
Mix the crème fraîche, fromage blanc, nutmeg, and salt and pepper in a bowl. Set aside.
Divide dough into 3 pieces. Working with 1 piece of dough at a time, roll the dough into a large oval shape about 10 X 5-inches and place on a floured wooden pizza peel. Spread 1⁄2cup of the cheese mixture over circle, leaving a 1⁄2-inch border around edge. Sprinkle with one-third of the bacon and onions. Transfer dough to the baking steel and bake until golden brown and crispy, 6 to 8 minutes. Serve immediately.
Repeat with the remaining 2 pieces of dough and toppings.
¼ cup crème fraîche
1 cup fromage blanc
1/8 teaspoon freshly grated nutmeg
Kosher salt and freshly ground black pepper
1 recipe Weir Dough
8 ounces smoked bacon, thinly sliced across the strip
1 medium yellow onion, halved and thinly sliced