In same skillet, brown the onion in remaining oil. Deglaze with the wine and add to the saucepan. Add the broth and bring to a boil. Cover and simmer gently for about 1 hour. Add the potatoes, duck, and stir to combine. Bring to a boil and simmer for 30 minutes, uncovered, or until the potatoes are tender. Adjust the seasoning. Let cool.