Blueberry Galette

Name: Blueberry Galette
Prep time: 30 min
Cook time: 30 min
Total time: 1 h
Cuisine: American
Ingredients: 500 grams fresh blueberries (4 cups; 18 ounces); 70 grams granulated sugar (1/3 cup); 18 grams cornflour/cornstarch (2 tablespoons); 15 milliliters lemon juice (1 tablespoon); 2 teaspoons lemon zest, packed; 20 grams finely minced fresh ginger (2-inch piece, peeled and minced; about 2 tablespoons); 1 sheet shortcrust pastry or pie crust, thawed according to package directions if frozen; 1 egg, lightly beaten; Demerara sugar, for sprinkling; Fresh thyme leaves, to garnish