Cooking duck legs in fat makes the meat incredibly moist delicious but not oily. There is no chance it will dry out and become tough and you are pretty much guaranteed amazing flavor. It’s also really easy to do.  To cure the meat, each duck leg should be sprinkled with coarse salt (like kosher salt) and then refrigerated for 24 hours. 

• Coat the Duck legs with the salt and place on a rack in the refrigerator overnight NOT covered.  The next day remove the salt with a pastry brush or a dry kitchen rag. 
• Melt the duck fat over a very low flame.  
• Place the legs in a deep roasting pan or a lasagna pan and submerge the duck legs completely in fat. 
• Cooking the duck “Confit” requires low heat for a long time. 
• Temperature of the oven should be 250°F/120°C and the time should be around 3 to 4 hours depending on the size of your legs. The goal is to have the meat fall easily off the bone. In fact, one sign that the duck is done is that the meat pulls away, exposing bone. 
• After being cooked, the meat can be served immediately or stored in the fat, refrigerated, for 3 to 4 weeks.
• If you are serving it immediately, place some duck fat in a frying pan under medium heat and when hot place the Duck legs skin side down and crisp for a few minutes.  You can achieve the same result on a cookie sheet under the broiler.