Blueberry Peach Galette

Ingredients

• 1¼ cups all-purpose flour
• 1 tbsp sugar
• ½ tsp salt
• ½ cup (1 stick) unsalted butter, cold and cubed
• 3–4 tbsp ice water
• 2 medium peaches, thinly sliced
• 1 cup fresh or frozen blueberries
• 2 tbsp sugar (plus more for sprinkling)
• 1 tbsp cornstarch
• 1 tsp lemon juice
• ½ tsp vanilla extract
• 1 egg (for egg wash)