Preheat oven to 375.
Heat 2 tablespoons duck fat (or olive oil) in a large cast iron skillet over medium high heat.
Sprinkle the duck skin with salt and pepper.
Place the duck legs into the hot pan, skin side down, cook until skin has browned, about 6 minutes. Flip the duck legs overs.
Place the cast iron skillet in the oven for 1 ½ to 2 hours or until the duck reaches 165F degrees. (If you don’t have a large enough cast iron skillet, just brown the duck legs and then transfer them, skin side up, to a baking dish). You can reduce the oven to 200 and keep the duck in the oven until ready to serve for up to 1 hour. To crisp the skin back up (of it becomes soft in the oven), preheat the broiler and place the duck under the broiler for a few minutes, keeping a very close eye to make sure the duck doesn’t burn.
While the duck is cooking make the cherry sauce. In a pot over medium high heat add the remaining 2 tablespoons duck fat. Add the shallots and cook until lightly browned, about 5 minutes. Stir in the garlic. Add the porter, cherries, smoked paprika, black pepper and honey. Allow to boil, stirring frequently, until thickened, about 8 minutes.
Spoon the sauce over the duck just prior to serving, or serve alongside.