Add 2 tablespoons oil to a saucepan over a medium heat, and sauté the shallots, garlic, and Thai chiles for 5 minutes, until fragrant.
Add the coconut milk, and stir together. Continue to cook another minute or so until thoroughly heated.
Remove from heat, and set aside to cool.
Add the coconut flakes to a dry skillet over a medium low heat. Toast, turning frequently, until they turn a medium brown color. Set aside to cool.
Add 1 tablespoon oil to the skillet, and cook the chopped peanuts for about 2 minutes, until browned.
Add about a quarter to a half-inch of water to a saucepan, and poach the shrimp until they are pink and curled into shape. Set aside.
Peel the pummelo using a sharp knife, taking as much of the thick white pith off as you can. Cut in half over a large bowl (to catch any juice). Cut into the membranes and release the flesh into the bowl. Break the segments into smaller, bite-size pieces.
Add the poached shrimp, toasted coconut flakes and peanuts, and cilantro leaves to the bowl with the pummelo – reserving a little of the peanuts and coconut flakes.
To the coconut milk mixture, which should be cooled by now, add the brown sugar, lime juice, and fish sauce. Stir dressing together, and season with salt to taste.
Pour the dressing over the salad mixture and toss gently.
Divide onto 4 plates, or serve on a platter. Top with the remaining coconut flakes and peanuts.