Zucchini Galette

For the crust

1. In a medium bowl, whisk together the whole wheat flour, all-purpose flour, sugar, and salt.

2. Add the cold cubed butter to the flour mixture and press each piece between your fingertips to flatten it.

   If your kitchen is warm, chill the flour beforehand so the butter stays cold and creates a flaky crust.

3. Pour 6 tablespoons of ice water into the bowl and stir with a fork until the water is absorbed into the dough.

4. Dump the shaggy dough out onto a clean work surface.

5. Use a bench scraper to chop and fold the dough repeatedly, gathering it back into a pile, until the butter pieces are about the size of peas.

6. Press the dough together into a flat square shape using the bench scraper to compact the sides.

7. Dust the work surface and dough lightly with flour.

8. Roll the dough flat with a rolling pin until it is about 1/2-inch thick.

9. Cut the dough into four equal quadrants using the bench scraper.

10. Stack the four quadrants on top of each other, tucking any loose crumbs between the layers.

11. Press the stack down firm with a rolling pin and shape it back into a round disk.

12. Wrap the dough disk tightly in plastic wrap and chill in the refrigerator until firm, at least 1 hour or up to 2 days.

    Then 60 min of waiting

For the filling

13. Heat a medium skillet over medium heat and melt 1 tablespoon of butter.

14. Add the sliced yellow onion to the skillet and cook, stirring occasionally, until lightly caramelized, 8–10 minutes.

    Then 8 min of waiting

15. Grate half of the zucchini using the large holes of a box grater.

16. Thinly slice the remaining half of the zucchini into round coins.

17. Add the grated zucchini and thyme sprigs to the caramelized onions in the skillet.

18. Season the pan with 1/2 teaspoon of salt and 1/4 teaspoon of black pepper.

19. Cook, stirring frequently, until the grated zucchini has released its water, reduced in volume, and begun to brown, 8–10 minutes.

    Then 8 min of waiting

20. Remove the thyme sprigs from the cooked zucchini mixture and transfer it to a medium bowl.

21. In the same skillet, cook the sliced zucchini coins over medium-high heat until lightly browned and softened, 3–5 minutes.

22. Transfer the sliced zucchini coins to a plate and set aside to cool.

23. To the bowl with the cooked grated zucchini, add the grated Gruyère, grated Parmesan, a pinch of nutmeg, a pinch of extra salt, and a pinch of pepper.

24. Pour half of the beaten egg into the filling mixture and stir well to combine, saving the other half of the egg to wash the crust.

To assemble and bake

25. Preheat the oven to 400°F (200°C).

26. Lightly flour your work surface and roll out the chilled dough disk into a rough 12-inch circle.

27. Transfer the rolled dough into the cooled medium skillet, letting the edges overhang the sides of the pan.

28. Spread the grated zucchini and cheese filling evenly over the bottom of the crust.

29. Arrange the cooked zucchini coins in a single layer over top of the filling, reserving the nicely browned pieces for the very top.

30. Sprinkle a light pinch of salt over the top of the arranged zucchini coins.

31. Fold the overhanging edges of the dough back over the outer edge of the filling, letting the folds fall naturally.

32. Brush the exposed folded edges of the pie dough with the remaining half of the beaten egg.

33. Bake in the center of the oven until the pastry is deep golden brown and the filling is set, 40–50 minutes.

    Then 40 min of waiting

34. Remove the galette from the oven and let it cool in the skillet for at least 15 minutes.

    Then 15 min of waiting

35. Sprinkle fresh thyme leaves over the top of the galette, slice into wedges, and serve.