This is one American classic I thought I’d never try to do at home. At the Platonic Diner in the Sky (Home of the “Pie in the Sky” and other ideals-you know the one) these are prepared perfectly and an optional side to every suitable main dish. There, the batter is crisp, brown and light, the onions soft and not the least stringy, but not mushy either. The rings are round, distinct, and never stuck…