In a large bowl, mix the wine, two-thirds of the onion, half of the garlic, the sesame oil, the fish sauce, half of the galangal and the chillies. Put in the rabbit pieces and turn to coat in the marinade. Cover in cling film and marinate in the refrigerator overnight.
Just before cooking, sear the rabbit pieces in 1 tablespoon of the sunflower oil in a heavy frying pan, and transfer to a plate. They should still be raw in the middle.
Add the remaining oil to the pan, and fry the remaining onion and garlic and the celery until softened, then add the remaining galangal and stir before returning the rabbit to the pan.
Add the stock with any remaining marinade, and season with salt and pepper. Add the lemon grass and lime leaves. Cover the pan and simmer for 10–15 minutes.
Check that the rabbit is done. Discard the lemon grass, and serve the rabbit immediately.