This sandwich really shocked us with how popular it’s been, but once you taste it, you will understand why. We use celery root, aka celeriac, this knobbly, gnarled joy of a winter vegetable. We cut it into planks, batter it with a tightly-crusted-panko breadcrumb topping, and gently fry it. We’re getting our celery root from Verrill Farm in Concord (thanks Verrill!) Also on the sandwich: a buffalo aioli, a smoky fava bean spread with a touch of Clover BBQ sauce, dill pickle coins, and a lovely cabbage-feta-black pepper sauce.