No, I did not grow up with matzo, the crackerlike Jewish bread eaten on Passover. But now, thanks to Jason, who is famous for his matzo brei (a kind of eggy scramble), I always keep a box of the stuff in my pantry for cooking experiments. Sometimes I go sweet, covering the matzo with melted chocolate, chopped nuts, and dried fruit; sometimes I go savory, crushing it into bits to make bread crumbs. Here I use matzo as the base for an open-face sandwich, spread with chive mayo and topped with two completely underappreciated supermarket ingredients: smoked trout and packaged steamed beets.