- Cut the spring onions finely lengthways and place on a bowl. Cut the carrots, cucumber and radishes in to fine matchsticks (this is easiest done on a mandliine) and add to the onions along with the salt, sugar and 3 tablespoons of the vinegar. Mix well to combine and set aside to 15 minutes, stirring occasionally.
- In a jug, combine the remaining one tablespoon vinegar with the soy sauce, chilli paste and stir to combine.
- Heat the oil in a frying pan over a medium heat and sauté the shiitake, brown mushrooms and garlic for about 5 minutes then stir in the soy mix and bring to bubbling. Cook for a few minutes to thicken the sauce then stir in the sesame oil and remove from the heat.
- In a bowl combine the mayonnaise and sriracha to taste.
To serve, pile some shiitake into the steamed bao and top with the vegetables, a spoon of mayo, coriander and a sprinkle of peanuts.