Wash vegetables. Peel the onions and carrots. Cut the leeks, carrots and onions into bite-sized strips. Cut the mushrooms into thin slices. Heat the oil in a saucepan and sauté the onions until they are golden brown. Add the vegetables, sauté, season with salt, pepper and sugar. Add the stock and bring to a boil for 5 minutes. Cut the glass noodles into bite-sized pieces and add them to the soup. Add the sesame oil to the soup and serve with chives.