Boil vinegar, mirin, and sugar in a pan, then simmer for 2-3 minutes until sugar dissolves.
Add Thai shallots, remove from heat, and pickle at room temperature for two hours.
Drain shallots and reserve the pickle solution for dressing.
Combine shallots, edamame, coriander, mint, chilli, and 30ml of pickle solution in a bowl.
Cut each poussin into four pieces and place in a large bowl.
Blend ginger, garlic, shallot, spring onion, plum wine, sauces, ao nori, olive oil, and miso into a paste.
Chop plums and add them to the marinade paste.
Coat the poussin in marinade and refrigerate for one hour.
Preheat the grill to its highest setting.
Sear poussin skin-side down in a hot griddle pan for 4 minutes per side.
Transfer meat to a foil-lined tray and baste with remaining marinade.
Grill for 12-15 minutes, basting occasionally, until cooked through and juices run clear.
Rest meat for 5 minutes, then serve topped with the pickle salad.