In a large nonstick skillet, cook the dried chiles, coconut, coriander and cumin over moderately high heat, shaking the skillet, until the coconut starts to brown, 1 minute; transfer to a blender. Add the ginger, garlic, tamarind and 1/2 cup of water and puree.
In the same skillet, heat the oil. Add the onion and jalapeños and cook over moderately high heat until the onion is golden brown, about 3 minutes. Add the puree and bring to a boil. Add the shrimp and cook over moderately low heat, turning a few times, until just white throughout, about 2 minutes. Remove the skillet from the heat and stir in the vinegar. Season with salt and serve right away.