Celeriac remoulade is the French answer to coleslaw. Shredded ribbons of celeriac are tossed in a sauce of mayonnaise, lemon, and mustard. Inspired by a dish I had at my favorite restaurant in Paris near Odeon, I mix in flecks of sweet-tart green shreds of Granny Smith apples for sweetness, crowned with nubs of jumbo lump crabmeat.