How to Make It
MAKE THE DUMPLINGS
Line a large baking sheet with parchment paper. Using a fork, stir together sausage, scallions, cilantro, egg, soy sauce, ginger, and sesame oil in a large bowl. Fill a small bowl with water. Lay 3 wonton wrappers on a work surface. Place 1 rounded teaspoon of sausage mixture in the center of each wrapper. Dip a finger in water and rub around the edge of each wrapper. Fold 1 side of wrapper over filling. Make 3 pleats along seam and pinch to seal. Transfer assembled dumplings to prepared baking sheet. Repeat with remaining sausage mixture and wrappers.
Add water to a medium nonstick skillet until bottom is just covered; bring to a simmer over medium-high. Add as many dumplings, flat side down, as will comfortably fit. Cover and steam until wrappers are translucent, about 3 minutes.
Pour off any water remaining in skillet. Add 2 tablespoons vegetable oil (if dumplings are sticking, shake skillet gently or loosen dumplings with a rubber spatula). Cook, undisturbed, until bottoms are golden and crispy, about 1 minute. Transfer dumplings to a paper towel– lined plate. Wipe skillet clean and repeat with water, remaining dumplings, and vegetable oil.
MAKE THE DIPPING SAUCE
Stir together all ingredients plus 1 tablespoon water in a small bowl until sugar dissolves. Serve with dumplings
Transfer uncooked dumplings on baking sheet to freezer. Freeze, uncovered, until firm, about 2 hours. Remove frozen dumplings from baking sheet and transfer to a resealable plastic bag. Freeze for up to 3 months. Cook as directed (do not thaw), adding 2 to 3 minutes to steam time.