Step 1

Make the dough: In a large bowl, mix together the flour, salt, and sugar. Add the chilled butter cubes and toss to coat. Using your hands, work the butter into the flour until the mixture resembles a coarse meal.

Step 2

Make a well in the center of the butter-flour mixture and pour in the buttermilk. Quickly form a shaggy dough with your hands.

Step 3

Turn the dough out onto a lightly floured surface and knead gently until it just comes together, being careful not to overwork it. Shape the dough into a 7-inch square, about 1 inch thick. Cut into 8 equal pieces and shape into discs. Wrap each disc in plastic wrap and refrigerate for at least 1 hour or overnight.

Step 4

Make the sauce: Heat the olive oil in a 12-inch oven-safe pan over medium-high heat. Sauté the onion, garlic, and bell peppers until soft, about 10 minutes. Season with salt and pepper, then add the crushed tomatoes and stir until well combined. Cook down for another 10 minutes, allowing the flavors to meld together, then remove from heat and add in the fresh basil.

Step 5

Assemble the galettes: Heat the oven to 400°F (200°C). Line 2 baking sheets with parchment paper.

Step 6

Roll out each disc of dough into a 7-inch round, trimming the edges for even circles. Spoon about 2 tablespoons of the tomato sauce into the center of each round. Arrange the sliced veggies in alternating patterns (eggplant, tomato, squash, zucchini) on top of the sauce, working from the outer edge to the center. Season with salt and pepper.

Step 7

Make the herb seasoning: In a small bowl, mix together the basil, garlic, parsley, thyme, salt, pepper, and olive oil. Spoon the herb seasoning over the vegetables. Fold the edges of the dough up and over the filling, leaving an opening in the center. Transfer the galettes to the prepared baking sheets, 4 per sheet.

Step 8

Bake the galettes: Brush the dough with an egg wash and sprinkle with flaky sea salt, if desired. Bake for 25 minutes, then rotate the pans and bake for another 10 minutes, until lightly golden.

Step 9

Remove from the oven and let cool slightly.

Step 10

Garnish and serve: Drizzle the balsamic vinegar and olive oil mixture over the galettes.

Step 11

Sprinkle finely chopped chives for a fresh garnish.

Step 12

Serve hot as a main dish or side. Enjoy!