1 pound boneless skinless chicken thighs, cut into chunks
1-1/2 cups sliced fresh mushrooms
1 small onion, cut into wedges
2 tablespoons hoisin sauce
2 tablespoons prepared mustard
2 tablespoons Sriracha chili sauce or 1 tablespoon hot pepper sauce
1 package (10 ounces) pot sticker or gyoza wrappers
1 large egg, lightly beaten
sauce:
1 cup reduced-sodium soy sauce
1 green onion, chopped
1 teaspoon ground ginger
In a food processor, combine chicken, mushrooms, onion, hoisin sauce, mustard and chili sauce; cover and process until blended.
Place 1 tablespoon chicken mixture in the center of 1 wrapper. (Until ready to use, keep remaining wrappers covered with a damp towel to prevent them from drying out.) Moisten entire edge with egg. Fold wrapper over filling to form a semicircle. Press edges firmly to seal, pleating the front side to form several folds.
Holding sealed edge, place each dumpling on an even surface; press to flatten bottom. Curve ends to form a crescent shape. Repeat with remaining wrappers and filling.
Working in batches, arrange pot stickers in a single layer on a large greased steamer basket rack; place in a Dutch oven over 1 in. of water. Bring to a boil; cover and steam until filling juices run clear, 5-7 minutes. Repeat with remaining pot stickers.
Meanwhile, in a small bowl, combine sauce ingredients. Serve with pot stickers. Refrigerate leftovers.