There is a lot that divides us as a country. And I’m not talking about politics. I write about food, which can be just as divisive. Ketchup with fries? Thick- or thin-crust pizza? Does avocado toast signal the end of times?Is a hot dog a sandwich??? Even when I’ve delved into what I thought were neutral topics — pound cake, cooking with apples and, uh, buckwheat waffles (really!) — the fists have come out.