Cheesy Summer Squash Galette with Tomato Vinaigrette – Small Pantry Recipes

Ingredients

• 1 recipe Easy Buttery Pastry Dough, chilled (See Tips below)
• 3 tablespoons Tomato Vinaigrette (or your favorite tomato jam (See Tips below))
• 1 cup shredded Gruyère cheese ( or young cheddar, plus more for sprinkling)
• 1 medium zucchini (very thinly sliced (⅛- to ¼-inch thick))
• 1/2 cup thinly sliced red onion (About ¼ medium red onion or 1 medium shallot)
• 1 tablespoon fresh thyme leaves (roughly chopped)
• Flaky sea salt (for sprinkling)
• 1 egg (beaten (Optional))