Combine hot water with sugar to dissolve. Add fish sauce, rice vinegar, lime juice, hot sauce and garlic. Reserve. Cook noodles 3 to 5 minutes in boiling water until just tender. Chill under cold water. Drain. Line a platter with lettuce, bean sprouts, herbs, cucumber and carrot. Fluff cold noodles on top. Combine sugar and water in a medium saucepan. Cook over high heat until mixture turns a golden caramel colour. Standing back, in case mixture bubbles and splatters, add water, garlic, lemon grass, shallots, fish sauce, soy sauce. Marinate chicken in this mixture for 1/2 hour to overnight. Heat oil in wok. Lift out chicken from marinade and add. Brown. Add liquid and cook until sauce becomes syrupy. Spoon chicken and sauce over noodles. Sprinkle with peanuts. Serve with reserved sauce over top or individually as a dip. NOTES : Makes 4 to 6 servings.