Photograph: Tara Fisher
Put the sweetcorn in a bowl with some salt and freshly ground black pepper, then sift over the polenta, flour and baking powder. Mix together, then mix in the egg. Cover and leave the mixture to rest for at least an hour in the fridge.
Heat a small wok or frying pan and add half the oil as soon as it begins to get quite hot. Add the garlic, ginger and chilli at once and stir over a medium heat until the garlic begins to colour, then add the desiccated coconut and stir constantly, making sure it doesn't burn. Once it begins to colour, toss in the prawns and continue to stir until the prawns begin to whiten. Tip everything out into a heatproof bowl, then place the wok back on the heat (don't wipe it).
Add the peanut butter and coconut milk to the wok, and stir well. Bring to the boil and cook until it's reduced to a thick paste. Return the prawn mixture to the wok and cook for 20 seconds, then add the Thai fish sauce, lime juice and coriander and tip into a clean bowl. Season to taste.
Heat a heavy-based or nonstick frying pan and give the corn mixture a good stir. Lightly oil the pan with the remaining oil and, in batches, drop dessertspoonfuls of the fritter mixture into it. Cook over a moderate heat until golden on each side.
To serve, top the fritters with the prawn mixture and garnish with coriander leaves and chopped chilli.
Get ahead: make the corn fritters the day before; chill. They can also be frozen. Warm through before serving