Rice Vermicelli: Bun Thit

Name: Rice Vermicelli: Bun Thit
Ingredients: 8 ounces dried rice vermicelli or 1 pound fresh bun; 8 romaine lettuce leaves, ribs removed, julienned; 2 carrots, peeled and julienned; 1/2 cucumber, peeled, seeded, and thinly sliced into crescents; 12 large mint leaves, julienned; Nuoc Cham, as needed, recipe follows; 5 tablespoons sugar; 3 tablespoons water; 1/3 cup fish sauce; 1/2 cup lime or lemon juice; 1 large clove garlic, minced; 1 or more bird's eye or Thai chiles, seeded and minced; 1 shallot, peeled, thinly sliced, and rinsed (optional)