VIETNAMESE CHICKEN AND PINEAPPLE SOUP

Steps:

• Cut peel from pineapple in a thin layer and discard, then trim outer layer of pineapple, cutting just deep enough to remove eyes but allowing pineapple to remain intact, and transfer trimmings to a blender. Quarter pineapple lengthwise and cut out core, then coarsely chop core and transfer to blender. Purée with 2 cups water until smooth. Pour through a fine-mesh sieve into a 2-quart glass measure, pressing hard on solids (discard solids), then add enough water to measure 8 cups pineapple broth.
• Cut remaining pineapple into 1/2-inch pieces and put in a bowl.
• Place chicken between 2 sheets of plastic wrap. Gently pound chicken 1/4 inch thick with flat side of a meat pounder or with a rolling pin. Cut chicken across the grain into 1/4-inch-wide strips and transfer to a bowl, then chill, covered.
• Heat 2 tablespoons oil in a 5- to 6-quart heavy pot over moderately high heat until hot but not smoking, then sauté chiles and 2 tablespoons garlic, stirring, until fragrant, about 30 seconds. Add 1/4 cup fish sauce and boil until sauce is reduced by half, about 2 minutes. (Fish sauce will be extremely pungent when first added but will have a mild flavor in soup.) Add pineapple broth and bring to a boil. Stir in pineapple pieces, mushrooms, tomatoes, bean sprouts, and 1/4 teaspoon pepper and return to a boil. Reduce heat and simmer, uncovered, stirring occasionally, 10 minutes. While soup simmers, heat remaining 2 tablespoons oil in a 12-inch heavy skillet over moderately high heat until hot but not smoking, then sauté remaining tablespoon garlic, stirring, until fragrant, about 30 seconds. Add remaining 2 tablespoons fish sauce and simmer until sauce is reduced by half, about 2 minutes.
• Sprinkle chicken with remaining 1/4 teaspoon pepper and add to garlic mixture, then sauté, stirring, until just cooked through, about 4 minutes.
• *Available at Southeast Asian markets and some specialty produce markets.