Instructions

1. Make the dough: Whisk together flour, salt and sugar in a medium bowl. Add butter and using a pastry cutter or your hands, incorporate the butter into the flour until the mixture resembles coarse crumbs.
2. Drizzle four tablespoons of water over the flour mixture; stir with a wooden spoon until clumps start to form. If the dough looks dry, slowly add more water, 1 tablespoon at a time, as needed. Gather dough together and form into a disc; wrap in plastic wrap and refrigerate for an hour.
3. Meanwhile, make the filling: Heat oil in a pan over medium heat. Add leeks and salt to taste and cook, stirring occasionally, until leeks soften and turn lightly brown, about 8 minutes. Add garlic, thyme, and nutmeg and stir until fragrant, about 1 additional minute. Turn off heat and set aside.
4. Preheat oven to 350°. Lightly dust a work surface with flour and place dough onto floured surface. Using a rolling pin, roll dough into a 12-inch circle, and gently transfer to a large baking sheet. Spread leek mixture in a thin, even layer on the circle, leaving 1½ inches of dough around the perimeter. Arrange zucchini slices in an even layer on top of the leeks; brush with oil and sprinkle with additional salt and pepper to taste. Bake until crust is lightly browned and zucchinis are cooked through, 50-60 minutes. Remove from oven and allow to cool slightly.
5. Combine ricotta and lemon zest in a small bowl. Slice galette into wedges and serve topped with a dollop of ricotta.