Cut ribs into 4 sections (about 3 ribs per section). Place ribs in a large pot. Cover ribs with cold water and heat on medium high heat until boiling. Once boiling, cook ribs 30 minutes.
After 30 minutes, remove ribs from water and let cool.
Meanwhile, make the marinade. Cut the tough bottom of the lemongrass stalk. Add lemongrass, soy sauce, brown sugar, sherry, peanut butter, olive oil, garlic, ginger and 1/2 red chili pepper into blender or food processor. Blend until almost smooth. Stir in coconut milk.
Place cooled ribs in a gallon sized zip-top bag and add marinade. Marinate ribs 30 minutes.
Preheat oven to 350°F.
Arrange ribs in a single layer in roasting pan. Add all of the marinade to the pan.
Roast uncovered 30-45 minutes, basting every 15 minutes with marinade.
Remove ribs from roasting pan, and pour marinade into a small bowl for sauce.
Brush sauce over ribs and serve immediately,