1 1/2 pounds medium shrimp $
9 1/2 cups water, divided
1/2 cup chopped peeled fresh galangal (about 2 ounces)
1/2 cup (2-inch) pieces peeled fresh lemongrass (about 4 stalks)
6 fresh or frozen kaffir lime leaves
1/2 cup canned straw mushrooms, quartered $
2 tablespoons roasted red chili paste (such as Thai Kitchen)
1 tablespoon fish sauce
2 Thai chiles
1/2 cup chopped green onions
1/2 cup chopped fresh cilantro $
1 tablespoon fresh lime juice
6 tablespoons chopped dry-roasted unsalted peanuts $
4 lime wedges