How to Make It
Shell and devein the shrimp, leaving the tails on 24 of them. Mince the remaining shrimp and transfer to a bowl. Stir in the water chestnuts, cilantro, cornstarch, sake, oil, sugar, salt and pepper.
Lay 6 of the gyoza skins on a work surface. Mound a scant tablespoon of shrimp filling in the center of each. Top with a whole shrimp, allowing the tail to stick out. Brush 6 more gyozas lightly with water and set them, moistened side down, on the shrimp. Press the edges gently to seal. Lightly brush the tops with water and bring the edges into the middle to form a purse, pressing down lightly. Continue with the remaining gyozas, filling and shrimp.
Arrange the purses in a steamer basket, seam side down. Set the basket in a pot over 1 inch of boiling water, cover and steam until the purses feel firm, 8 to 10 minutes.
Meanwhile, in a small bowl, combine the soy sauce and chili-garlic paste. Transfer the purses to a platter and serve with the sauce.