Combine 2 cups flour, cubed cold butter, and salt to a food processor. Pulse until the butter is about the size of peas. Add ice water and vinegar, and continue to pulse until the dough begins to come together. Dust a clean work surface with flour, transfer the dough to the surface, and knead until no dry spots remain. Avoid overworking. Wrap in plastic wrap and chill in the fridge for at least one hour.

After chilling and resting, Roll out into a large circle until the dough is about 1/8 inch thick. Carefully transfer to a sheet tray lined with parchment.

Preheat oven to 400.

Slice your tomatoes to about ¼-⅓ of an inch thick. Salt both sides, and transfer to a towel-lined sheet tray and cover with towel overtop. Allow the tomatoes to release their excess moisture for at least 10 minutes.

Spread about ¼ cup of basil pesto in the center of the dough, leaving about 1-2 inches of dough for the crust. Layer the mozzarella cheese and then working from the outside in, arrange the tomatoes

Fold the crust over the edges of the tomatoes. Brush the exposed crust with egg wash and sprinkle with parmesan. Top everything with flaky salt.

Transfer to preheated oven and bake for 45-55 minutes.

Allow the galette to cool on the hot sheet tray for about 10 minutes before garnishing with fresh basil, salt, pepper and/or olive oil.