Beef and Curry Pie

Name: Beef and Curry Pie
Ingredients: 1/2 pound ground beef chuck (not lean); 1 tablespoon soy sauce; 1/2 teaspoon sugar; 1/4 teaspoon salt; 1 teaspoon vegetable oil; 1 medium onion, chopped (1 cup); 1 tablespoon curry powder (preferably Madras); 1 large russet (baking) potato, peeled and cut into 1/4-inch pieces (1 cup); 6 tablespoons water; 1/4 cup frozen peas, thawed; 2 (17 1/4-ounce) packages frozen puff pastry sheets, thawed; 1 large egg, lightly beaten; parchment paper; a 5-inch round cookie cutter