Mix 2 cups of all-purpose flour and ½ teaspoon of salt. Add 2 tablespoons of olive oil and ½ cup plus 2 tablespoons of lukewarm water and knead into a smooth dough, adding a little more water if it is dry or flour if it is sticky.
Cover and rest at room temperature for 30 minutes. Meanwhile, preheat the oven to 425°F / 220°C and line a baking sheet with parchment paper.
Roll out the dough thinly on a floured surface and lay it on the baking sheet. Spread with ¾ cup of crème fraîche, then scatter with 1 medium thinly sliced yellow onion and 3 slices of bacon, cut into thin strips.
Season with salt and black pepper. Bake on the middle rack for 14-18 minutes, until the edges are crisp and lightly browned and the bacon is cooked.
