Pour the lime juice on the chicken and let stand while you prepare the rest of the soup. In a medium saucepan, place the coconut milk, lemon grass, grated lime peel, galanga or ginger, and (optionally) chiles. (The optional part is that if you don't want the whole dish to taste spicy, add the chiles later; the earlier you add them, the hotter the resulting dish.) Bring the coconut milk to a simmer. When the soup is simmering, add the lime-soaked chicken pieces and stir to distribute them. Reduce the heat so the soup stays just below a boil and cook for 12 to 15 minutes, or till the chicken pieces are finished cooking. Remove from heat and serve immediately with fresh cilantro leaves for garnish. Now, the best way I ever had this soup was with pieces of fresh grouper instead of chicken. I also added slices of kumquats instead of the ginger, and used the sweet Fresno chiles instead of Thai birds. We also served it over Vietnamese rice noodles. Was it southeast Asian or Caribbean? Who cares, it was wonderful. If you can't find grouper, it'd be good with any tender, delicate white fish ~sole, maybe, or a very fresh sea bass, or maybe little chunks of monkfish. I believe I've had this with shrimp as well. (Grouper, BTW, is a type of fish common in the Caribbean and, if I recall, in other warm-water parts of the world; the flesh is very white, very tender, and quite delicately flavored. I've seen it in one Asian grocery store in the Bay Area, as well as in the Bahamas, so I'd guess that Gulf Coast netters should be able to find it readily.)