Cut onions into strips and fry them in oil until translucent. Dissolve palm sugar in 3/8 litres of hot water. Bring everything to the boil with two tablespoons of oyster sauce, vinegar and turmeric. Stir cornstarch in a little cold water until smooth.
thicken the sauce with it. Peel and finely chop the ginger. Stir in the remaining oyster sauce and season to taste with a little pepper. Put the prawns on skewers and fry them in the fat on both sides for about two minutes.
Season with pepper. Garnish with tomato and radish flowers and radish. Add the sauce.