Foryoueats: Pork Shumai (Steamed Pork Dumplings)

Ingredients

• For the Filling:
• ¾ onion (7 oz, 200 g)
• 2½ Tbsp potato starch or cornstarch
• 14 oz ground pork (⅞ lb)
• 1 tsp ginger (grated, with juice; from a 1-inch, 2.5-cm knob)
• 1 Tbsp sake
• ½ Tbsp toasted sesame oil
• 2 tsp sugar
• 1 Tbsp soy sauce
• ½ tsp Diamond Crystal kosher salt
• ⅛ tsp white pepper powder
• For the Dumplings:
• 35 wonton wrappers
• 3 Tbsp green peas (1 oz)
• For the Dipping Sauce:
• soy sauce
• rice vinegar (unseasoned)
• la-yu (Japanese chili oil) (optional; store bought or make myHomemade La-yu)
• Japanese karashi hot mustard (optional)