The variables can be daunting, starting with the pasta itself: fresh or dried, skinny or fat, long or stubby. Rigatoni may be most common, but spaghetti and ziti and shapes with tongue-twisting names are all fair game. Eggplant comes in different shapes and sizes as well, sometimes cooked down into such an advanced state of melty sweet intensity that it nearly vanishes into the sauce; other times, it’s handled separately, grilled or roasted, and draped directly over the pasta. Finally, the finishing touch: ricotta, fresh or dried. The former hits the hot noodle and fuses with the tomato to create something more pink than red; the latter, the traditional way to goose this Sicilian staple, lives on independently, a blizzard of hard cheese that speckles the noodles with salty bites. The only common denominator? A few leaves of basil to make it pretty.

Pasta alla norma was born in Catania, Sicily’s second city, a hot mess of a port town bathed in the shadows and sulfur of Mount Etna. “Standard pasta” is not a particularly flattering name for a dish as iconic as this, but legend has it that Nino Martoglio, a 19th century Cantanian playwright with one of history’s greatest mustaches, took a bite of the tomato-eggplant-ricotta combination and declared it the standard by which all other pastas be judged.

My entire caloric intake yesterday was dedicated to the form, first at Antica Sicilia in the heart of old Catania (where this picture comes from), later at U Fucularu, where we our midnight noodles came with a side of accordion music and a punishing dose of humidity. In a country where changing a single ingredient in a pasta recipe is considered sacrosanct, it was shocking to taste two pastas bearing the same name with such vastly different characters.

Pasta alla norma never made it big in America, at least not in its original form. But if you consider that for the impoverished residents of this island, eggplant has long been treated like meat, it’s easy to see the connection to Italian-American staples—particularly baked ziti. Somewhere along the way norma lost the eggplant, replaced by sausage or a blanket of mozzarella or both. The end result, though, has the same DNA: a fusion of sweet, acidic tomato, salty deposits of dairy, and a deep savory bass line left behind by the meat or eggplant. Plus, of course, a bit of basil to make it pretty.