Wash scallops, dry, season with salt and pepper and sprinkle with lemon juice. Peel avocado and mango, remove seeds and cut into slices, put on a la carte dish. Chop onion, mix with chilli, oil and vinegar, salt and pepper and add a pinch of sugar, let it brew. Melt the butter in a frying pan, fry the scallops on both sides for 2-3 minutes. Lay onion vinaigrette out on fruits and arrange the scallops on top.