Preheat oven to 300 degrees.
Chicken:
Melt duck fat in Dutch oven over medium high heat. When melted and starting to sizzle, slowly add the chicken, skin side down. Cover with your screen and allow to cook for 6-7 minutes or until deeply browned. Carefully turn chicken over and cook on the other side for 3 minutes. Set to the side on a platter.
Bacon:
Add chopped bacon to the pot. Cover with your screen and cook for 4 minutes, stirring frequently. Set to the side on the platter with the chicken.
Sausage:
Add the sausage to the pot. Cover with your screen and brown the sausage, turning periodically to brown both sides. This should take about 4 minutes. Set to the side with the chicken and bacon.
The Vegetables:
Drain all but 2 tablespoons of the fat from the pan. Reduce heat to medium. Add the onions, scraping the brown bits on the bottom of the pan. Cook until the onions are translucent, about 4 minutes. Slowly add the stock and continue scraping the brown bits off the bottom of the pan. Add the garlic, parsley, celery, carrot, bay leaves and beans. Stir to incorporate. Increase heat to high and bring to a simmer. Reduce the heat to low and cover the pot. Continue cooking for 45 minutes or until the beans still have a slight bite.
Putting It All Together:
Remove the celery, carrot, parley and bay leaves. Add the sausage and bacon and submerge into the beans. Place the chicken legs on top, skin side up. The beans should be submerged in the stock and the chicken laying on top. Put the Cassoulet into the oven (uncovered) for 2 hours.
Check to ensure there is enough liquid and the beans are submerged. Add a little water to the edge of the pan if it seems to be a little dry. You don’t want to pour water on top or it will break the crust that’s forming. Cook an additional 3-4 hours, checking periodically and adding water if needed.
After 5 hours, you can add a little water to the edges and turn your oven down to 150 degrees. You can hold till you’re ready to serve. Periodically check to ensure it doesn’t need a little more water. You don’t want it to dry out.