Northern Chinese Beef Dumplings

Name: Northern Chinese Beef Dumplings
Prep time: 10 min
Cook time: 25 min
Total time: 35 min
Cuisine: Asian, Chinese
Ingredients: 24 gow gee or gyoza wrappers (or try my homemade dumpling wrappers); chilli oil, to serve (try my homemade chilli oil); soy sauce, to serve; coriander leaves (cilantro), finely chopped, to serve; spring onions (scallions), finely sliced, to serve; 1 tsp cumin seeds; 1 tsp Sichuan peppercorns; 200g (7 oz) beef mince; 1½ tbsp soy sauce; 1 garlic clove, finely chopped; 3 tbsp finely chopped coriander (cilantro); 1 tbsp finely grated ginger; 1 tsp cornflour (cornstarch); 2 tbsp water