Homemade Berry Turnovers

Bahan-bahan (9 porsi)

• 1 teaspoon cornstarch
• 1 teaspoon warm water
• 1 cup (about 150g) mixed berries (I use 1/2 cup blueberries, 1/4 cup halved blackberries, 1/4 cup chopped strawberries)
• 1 and 1/2 Tablespoons (18g) granulated sugar
• 1 teaspoon lemon juice
• 1 and 1/3 cups (166g) all-purpose flour (spooned & leveled), plus more for generously flouring hands, surface, and dough
• 1 teaspoon granulated sugar
• 1/2 teaspoon salt
• 3/4 cup (12 Tbsp; 170g) unsalted butter, very cold and cubed
• 6 -8 Tablespoons (90-120ml) ice cold water
• 1 large egg*
• 2 Tablespoons (30ml) milk
• optional: coarse sugar for topping
• optional: vanilla icing