Preparation

Make the shu mai

• Combine the shrimp, garlic, ginger, lemongrass, scallion, egg white, soy sauce, fish sauce, and sesame oil in a food processor. Pulse until the shrimp is finely chopped. Do not overprocess: the mixture should be textured rather than entirely smooth.
• Make a circle with your thumb and index finger. Place a wonton wrapper on top, nudging it down with your other fingers to create a cup. Add 1/2 Tbs. filling and bring the sides into the center, pleating and folding to seal. The tops should remain open, exposing the shrimp mixture. Repeat with the remaining wrappers.

Make the dipping sauce

• Combine the soy sauce, rice vinegar, honey mustard, fish sauce, and sesame oil in a medium bowl. Whisk to combine.

Steam and serve

• Set up a bamboo or conventional steamer over medium heat. Grease the bottom lightly with vegetable oil.
• Place the filled wonton wrappers, in batches if necessary, into the steamer. Steam until the shrimp is cooked through and the filling is set, 8 to 10 minutes. Remove to a serving platter and garnish with red chiles and scallions. Serve immediately with the dipping sauce.