Spicy Noodle Soup

11/2 teaspoons blacan (shrimp paste) 2 thick or 3 thin stalks fresh lemongrass 11/2 tablespoons chopped peeled fresh or frozen galangal 1 tablespoon chopped peeled fresh ginger 1 tablespoon chopped peeled fresh or frozen turmeric or 1 teaspoon turmeric powder 1 medium onion, chopped 6 fresh hot red chiles (such as Thai or serrano), seeded if desired and chopped 2 garlic cloves, chopped 5 candlenuts (do not eat raw) or macadamia nuts, chopped 2 tablespoons water 6 fried bean-curd puffs 2 chicken breast halves with skin and bones 31/2 cups chicken stock (preferably homemade) 6 oz fresh bean sprouts (21/2 cups), threadlike tails discarded 1/2 cup olive or vegetable oil 14-oz can well-shaken unsweetened coconut milk 1 tablespoon sugar 1/2 lb medium shrimp, shelled and deveined 1 lb fresh round (not flat) rice noodles or wheat noodles or 1/2 lb dried egg noodles Garnish: fresh cilantro sprigs