From the New York Times. Feel free to use any combination of cooked vegetables instead, even leftovers from the fridge. You’ll need three cups total.
FOR THE DOUGH:
2/3 cup all-purpose flour
2/3 cup rye flour or whole-wheat flour
1 large egg
Heavy cream, as needed
1 stick unsalted butter, cut into big pieces
2 teaspoons lemon juice
1/2 teaspoon grated lemon zest (optional)
FOR THE FILLING:
2 medium eggplant (about 1 pound), trimmed and thinly sliced
2 medium zucchini (about 3/4 pound), trimmed and thinly sliced
1 pound plum tomatoes, cored and thinly sliced
Extra-virgin olive oil, as needed
Kosher salt, as needed
Black pepper, as needed
2 hot chile peppers, such as cherry peppers, seeded and minced (optional)
3 ounces goat cheese, softened
1 small garlic clove, grated or pressed
1 teaspoon thyme leaves
1. In a food processor fitted with a steel blade, or in a large bowl, pulse or mix together the flours, sugar, and salt. In a measuring cup, lightly beat the egg, then add just enough cream to get to 1/3 cup. Lightly whisk the egg and cream together.
2. Add butter to flour mixture and pulse or use a pastry cutter or your fingers to break up the butter. If using a food processor, do not over-process; you need chickpea-size chunks of butter. Drizzle the egg mixture (up to 1/4 cup) over the dough and pulse or stir until it just starts to come together but is still mostly large crumbs. Mix in lemon juice and zest if using.
3. Put the dough on lightly floured counter and knead to make one uniform piece. Flatten into a disk, wrap in plastic and chill for 2 hours, or up to 3 days.
4. When you are ready to make the tart, roll out dough to a 12-inch round (it can be ragged). Transfer to a rimmed baking sheet lined with parchment paper and chill while preparing the filling.
5. Heat oven to 425 degrees. Spread out eggplant, zucchini and tomatoes in one layer on three separate sheet pans or cookie sheets. Drizzle generously with oil and season with salt and pepper. Roast vegetables, tossing zucchini and eggplant occasionally, 35 to 40 minutes. Eggplant and tomatoes will be golden at the edges; zucchini will be tender. Don’t let the vegetables get too dark because they will continue to brown in the tart. Transfer vegetables to a bowl (you want to have about 3 cups of them) and toss with chile peppers.
6. Decrease oven temperature to 400 degrees. In a small bowl, combine goat cheese, garlic and thyme leaves. Spread mixture in a thin layer over crust, leaving a 1 1/2-inch border all around. Arrange vegetables evenly over goat cheese. Fold up edges of crust, pleating to hold it in (sloppy is fine). Brush pastry generously with leftover egg and cream mixture.
7. Transfer galette to oven and bake until golden brown, about 40 minutes. Cool on a wire rack for at least 20 minutes before slicing.