Steak, peas, and carrots are a familiar trio, and usually not very exciting. Here, each element is transformed: a smoky spice rub on seared flank steak, crispy snap peas brightened with rice vinegar, and a silky carrot mash. Chop the carrots to about 1/4-inch pieces so they cook through evenly, otherwise the mash may have a few lumps. The grain of the meat refers to the direction of the muscle fibers (in flank steak, they run lengthwise). Cut across the grain, or across the width of the steak, to break up the fibers for slices that are tender, not tough.
