Bring a large pot of salted water to a boil. Mix kasha with the egg until grains are thoroughly coated. Heat oil in a sauce pan. Add onions and cook until they begin to soften, about 2 minutes. Add white wine vinegar and water, cover and cook until onions are tender, about 8 minutes. Uncover and evaporate liquid over high heat; continue to cook until onions are golden. Meanwhile bring chicken broth to a boil and add pasta to the boiling water. Stir sugar into onions, then add kasha and saute, over low heat until kasha is tender, about 5 to 8 minutes; adjust seasoning. Serve over bow tie pasta and dollop with sour cream and dill.