For rub, in a food processor or blender combine green onions, lemongrass, ginger, garlic, lime juice, and oil. Cover; process to a thin paste. Rub paste onto chicken.
Place chicken on the grill rack directly over medium heat; grill for 12 to 15 minutes or until chicken is no longer pink (170 degrees F), turning once halfway through grilling.
To serve, slice chicken. On 4 dinner plates, arrange chicken slices and Cilantro Rice noodles. If desired, serve with lime wedges. Makes 4 servings.
Cilantro Rice Noodles
In a large saucepan, cook rice noodles in a large amount of boiling water for 3 to 4 minutes or just until tender; drain. Meanwhile, in a large bowl, combine fish sauce, lime juice, brown sugar, and garlic; stir until brown sugar is dissolved. Add noodles, carrots, cilantro, and peanuts; toss gently to coat. Makes 4 cups.