With a sharp knife, score the duck legs through the skin without cutting the flesh. Season with salt and pepper.
Light a campfire and let it burn down to a steady, medium hot flame. Arrange the grill over the fire, severak inches away. You will need to adjust the fire and pan position to regulate the heat. You can also use an outdoor stove — or make the same recipe on your indoor range.
In a large cast iron skillet, add the olive oil. Add the duck, skin side down, and brown. Turn and brown the other side. Remove the duck legs to a piece of foil and let rest.
Pour the accumulated duck fat out into a heat-proof container — save for a few minutes.
Add the sausage to the pan and brown on both sides. Remove to the foil.
Drain the sausage fat and dispose of it. Wipe the pan. Add back the duck fat. When heated, add the onions, carrots, celery, bay leaf, salt and pepper. Stir well and cook until just barely soft.
Add the white wine and let cook a minute or two.
Drain the white beans and add to the vegetables. Stir. Add the meat back to the pan. Pour in enough water to rise 1/2 inch up the pan. Bring to a boil, then move the pan to the least hot part of the fire, or lower the flame to a simmer. Cover tightly with a lid or aluminum foil and let cook for 20-30 minutes. Uncover and serve. This is a lot of food for two hungry people.