Tossing the potatoes in vinegar while they’re still hot helps them absorb seasoning more deeply, ensuring every bite is well-seasoned rather than bland at the center. Using jammy egg yolks creates a richer, more emulsifiable base for the dressing, giving it a smoother texture and deeper, eggier flavor than standard mayo alone. There are two kinds of picnic people in this world: the ones who make deviled eggs and the ones who make potato salad. This recipe is for the overachievers, like me, who look at that division of labor and say, “No, actually, I’ll be doing both.” It’s the best of both in one bowl—a make-ahead side that’s just as at home at Easter brunch as it is at a backyard cookout. Deviled egg potato salad could go very wrong. In less careful hands, it might become a bowl of beige mush with a sulfur problem.…