Place noodles in a large bowl. Add enough hot tap water to cover; let stand for 10 to 15 minutes or until pliable but not soft. Drain well in a colander.
Meanwhile, for peanut topping, combine peanuts and lime peel; set aside.
In a small bowl combine fish sauce, lime juice, brown sugar, rice vinegar, and chile sauce; stir until smooth. Set aside.
In a 12-inch nonstick skillet heat 1 tablespoon of the oil over medium-high heat. Add chicken and garlic; cook and stir for 6 minutes until chicken is tender and no pink remains. Transfer to a bowl.
Add egg to the hot skillet and cook for 30 seconds. Turn egg with spatula and cook for 30 to 60 seconds more, just until set. Remove and chop egg; set aside.
In same skillet heat remaining 2 tablespoons oil over high heat for 30 seconds. Add drained noodles and sprouts; stir-fry for 2 minutes. Add fish sauce mixture and chicken; cook 1 to 2 minutes more until heated through. Divide noodle mixture among four plates. Sprinkle each serving with egg and peanut topping. Garnish with green onion and cilantro. Makes 4 servings.