For this simple skillet side, we thinly slice Brussels sprouts, apples and shallot so they cook quickly and absorb flavors. A food processor fitted with a slicing disk is the fastest, easiest way to do the prep, but if you prefer, you could use a sharp chef’s knife. To create layered texture and taste, two of the three sliced apples hit the skillet several minutes ahead of the remaining apple, sprouts and shallot; this gives them time to soften and for their flavors to concentrate. This is an excellent accompaniment to pork chops, a pork roast or roasted turkey.