Blend in blender, lemon grass, lime juice, garlic, shallot, galangal, and water about 2 minutes and set aside. Chop peppers fine. Set aside. Heat oil in large pot, add 1/2 cup of coconut milk, simmer until oil separated from the milk Add the spice paste and simmer for 5 minutes. Add fish sauce, sugar, salt, shrimp paste and chicken. Cook for 10 minutes. Add broth and remaining coconut milk. Return to a simmer, add peppers and peas and cook, partially covered, for another 15 minutes. Garnish with basil and chiles. Serve with rice.