Somehow, over the past few years, Neapolitan pizza — gooey, thin, soft-crusted, mozzarella-and-tomato-only — has become the ideal. In a way it’s understandable; pizza had strayed so far from its roots that the classical model was bound to come back.

But the Neapolitan version, classic as it is, is not necessarily the highest expression of the form. There are other legitimate pizzas, and chief among these is the Roman-style pizza al taglio — ‘‘by the cut,’’ which mostly refers to how it’s sold — a crisp, sturdy, thick-crusted pie that can be topped with anything (within reason) and is almost as good served at room temperature as it is straight from the oven. (Oddly, even in second-rate New York pizzerias, we’re still presented with a choice between Neapolitan-style triangular slices and ‘‘Sicilian,’’ a relative of pizza al taglio.)

The thing about Neapolitan pizza is that it is practically legally defined; you can’t mess around with it and still call it Neapolitan. Neither can you make it at home — you need special flour and tomatoes, local cheese and basically 1,000 degrees of heat. Roman pizza, on the other hand, can be varied almost infinitely and made anywhere. So maybe it shouldn’t be so surprising that the best pizza al taglio I’ve tasted in the last few years — including all but a couple in Rome itself — can be found in Pittsburgh, at Bread and Salt Bakery, the scrappy place owned by 39-year-old Rick Easton.