Cook the noodles according to the package instructions and drain well. Meanwhile, heat the oil in a very large frying pan or wok and cook the garlic and onion for 3 minutes, or until beginning to soften. Add the peppers and zucchini and cook for another 15 minutes over medium heat, until beginning to soften and brown. Add the peanuts and cook for 1 minute more. Whisk together the olive oil, grated lemon zest and 3 tablespoons of the lemon juice, the chile, chives and balsamic vinegar to taste. Season with salt and pepper. Toss the noodles into the vegetables and stir-fry to heat through. Add the dressing, stir to coat and serve immediately, garnished with fresh chives.
Serves 4