Jewish kosher cooking traditionally uses chicken fat (schmaltz) instead of butter when cooking meat, since mixing dairy and meat products is a definite no-no. Many markets sell tubs of rendered chicken fat. If so, buy a tub or two and, although it’s not essential, I always melt it down with minced yellow onions, to make it incredibly savory in both aroma and flavor.
Gribenes (cracklings) are bits of chicken skin that are fried crisp during the rendering process. These small, crunchy treats add intense flavor to breads and also make a delicious garnish for chopped chicken liver. (To add them to yeast breads, knead some crisp gribenes into the dough after the first full rise.)
Another way to obtain a flavorful version of rendered chicken fat is to make stock! After straining, and chilling the strained liquid, instead of throwing the congealed fat (that will have risen to the top of the liquid) away, spoon it into a tub and freeze it. Use as you would chicken fat rendered down with onions.
If your market doesn’t sell chicken fat, each time you roast a chicken, pull any wads of fat out of the cavity and snip them into smallish pieces, using kitchen scissors, and store them in a doubled freezer bag. (Do this with any extra flaps of skin, as well, and add this to the bag.) When you’ve accumulated a stash of at least 2 cups, then render the fat down by cooking in a skillet with some minced yellow onion (over low heat) until all the fat has melted and becomes liquefied, the onions become golden and the pieces of skin become nice and crisp (called Gribenes).