In a sealable plastic bag combine chicken with garlic, gingerroot, and 1 tablespoon vinegar and marinate, chilled, 1 hour.

Prepare grill.

Discard marinade and grill chicken on a lightly oiled rack set 5 to 6 inches over glowing coals 4 minutes on each side, or until just cooked through. Transfer chicken to a plate and keep warm, covered.

In a small saucepan heat coriander, parsley, broth, and oil until mixture just begins to boil and in a blender purée until smooth. Stir in remaining 1/4 cup vinegar and season with salt and pepper.

In a 6-quart kettle bring 3 1/2 quarts salted water to a boil and cook noodles 2 minutes. Stir in 1 cup cold water and bring to boil again. Repeat procedure 2 times and simmer noodles until just tender, about 5 minutes. Drain noodles in a colander and rinse under cold water.

Cut chicken crosswise into 1/2-inch slices. Divide dressing among 4 shallow bowls and top with noodles, chicken, sprouts, and scallions.

Each serving about 370 calories and 6 grams (14% calories from fat).