Heat sesame oil in sauté pan to smoke point, then add the beef. Sauté, turning frequently, until cooked nearly through. Pour off about half of excess oil. Add bell peppers and sauté. Deglaze with lime juice, add soy, vinegar, stock, pasta, and 2/3 of the green onion and heat pasta through, tossing with liquid. Add nectarines and briefly toss. Center pasta into the bowl, with sauce, meat, and vegetables around it. Garnish with remaining green onions and bread sticks. Serves 2.