Peel the pomelo, remove the membrane, loosely break out the segments, and put in a mixing bowl.
Put the coconut flakes in a heat-proof dish in the toaster oven, and toast till golden brown, about 3 minutes (watch closely to avoid burning)
Crushed the peanuts and set aside
Boil a pot of water, poach the prawns till they turn pink and cooked (careful not to overcook as the prawns would shrink). Remove and drain.
In a skillet, heat the oil, add the minced shallots, garlic and chili, stir fry for a few minutes till aromatic and confit-like. Add the coconut milk, heat through, without boiling. Pour in a medium bowl to cool.
Add the fish sauce, lime juice to the medium bowl, add the toasted dry coconut. Mix well to make the dressing. Taste before adding the sugar as the dressing should be a little tangy. Only add the sugar if the pomelo is on the sour side.
Just before serving, carefully toss the poached prawns, pomelo and dressing. Put on a serving platter, sprinkle the cilantro, crushed peanuts and crispy fried shallots (if using) on top and serve immediately.