Combine the meat, soy sauce, ginger, sesame oil, green chilli and sesame seeds. Mix the boiling water and flour in a food processor. Leave the dough to rest for 15 minutes. Roll out the dough approx. 2 mm thick. Cut out circles and place a spoonful of meat filling on each of them. Lightly brush the edges with a little water and firmly pinch the dough together. Whisk the egg and salt and gently add the oil for a creamy mayonnaise. Add the lime juice and sriracha to taste. Steam the dumplings in a bamboo steamer for approx. 10 minutes. Serve with chilli mayo.