Bring a large pot of salted water to a boil. Put the frozen peas in and let cook 3-4 minutes (from the time you put them in, not when it starts boiling again.)
(If you’re using fresh peas, cook them 4-5 minutes).
Drain them and pour them in a large bowl of cold water and ice cubes.
Wash the herbs and microgreens. Chop the chives and parsley with scissors. Cut off the dark green ends of the spring onions, keeping only the bulb and light green stem. Wash and chop the onions (*see note above on soaking).
Prepare the dressing by combining all the ingredients.
Drain the peas, mix with onions and herbs.
Just before serving, add in dressing and mix well.