Cherry Tomato Galette with Cheddar-Thyme Crust

Directions

1. FOR THE CRUST: In a food processor, pulse flours and salt to combine about 3 times. Scatter butter pieces over the flour mixture, then pulse until the butter is about the size of chickpeas, about 8 short pulses. Add the cheese and thyme, and pulse once or twice to evenly integrate. Sprinkle 2 tablespoons of water over mixture and pulse a few times, then repeat with 1 tablespoon of water at a time, or just until small curds start to form and dough holds together when pinched with fingers. It’ll look kind of crumbly but that's okay. (Alternatively, you can do this by hand.)
2. Empty dough onto clean counter or piece of wax paper. Using bench scraper, gather dough into a rough rectangular mound about 12 inches long and 4 inches wide. Starting from the farthest end, use the heel of your hand to smear about one sixth of dough against your work surface away from you. Repeat until all of your dough has been smeared. Using bench scraper, gather the dough again into a 12-inch long and 4-inch wide mound and repeat smearing of dough with heel of hand. The dough should be smooth and cohesive at this point; if not, repeat smearing process again. Form dough into 4-inch disk, wrap in plastic, and refrigerate until firm about 1 hour, or up to 3 days. The smearing process creates long layers of butter in the dough, which translates to long flaky layers in the cooked crust.
3. Heat the oven to 400° F while preparing filling and assembling galette.
4. FOR THE FILLING: In a large sauté pan over medium heat, heat 2 tablespoons olive oil. Add the onions, stirring to coat them evenly in the oil. Once the onions have started to color, lower the heat, stir in a few pinches of salt and pepper, and cook until the onions are a golden, amber color—about 25 to 30 minutes. Remove from the heat and let cool.
5. In a small bowl, stir together the ricotta cheese, 1 teaspoon olive oil, and salt and pepper, to taste. Meanwhile, on a large plate or cutting board, sprinkle the cherry tomatoes with salt; let them sit while preparing the dough to draw the juices out.
6. TO ASSEMBLE AND BAKE: On a lightly floured work surface, roll dough into a 12-inch round, dusting with flour as needed. (Don’t worry if your dough isn’t perfectly round.) Transfer the dough to a parchment-lined baking sheet. Spread the caramelized onions over the dough, leaving a 2 1/2-inch border around the edges, then top with the ricotta cheese mixture, spreading it evenly over the onions, then the cherry tomatoes. Fold the edges of the dough over the filling, pleating it in several places to hold in the filling. Lay a few sprigs of thyme over the tomatoes. (If your dough is getting too warm at any point and is difficult to manage, return it to the refrigerator for 10 to 15 minutes, then proceed.)
7. Bake for 40 to 45 minutes, until many tomatoes are bursting and the crust is golden. Cool for at least 20 minutes on wire rack. Serve warm or at room temperature.