Tostadas de Ceviche de Sierra Mazatleco

This is a Sinaloa dish. More specifically, it is from Mazatlan, the Pacific port city where the sierra boats come in at dawn and the marisquerias open by ten in the morning. If you order ceviche de sierra anywhere on the malecon, this is what arrives: a fine pink-white hash of cured fish bound with grated carrot, mounded high on a tostada, with Salsa Huichol and a slice of avocado on top.

The carrot is the tell. Outsiders who have never eaten ceviche in Mazatlan see grated carrot in a ceviche recipe and assume it is a stretch ingredient, something to make the fish go further. They are wrong. The carrot is structural. Finely grated, it disappears into the cured fish and gives the mixture body, a faint sweetness against the lime, and the soft texture that makes a Mazatlan ceviche unmistakable. Use the small holes of the box grater. Use a food processor and you have ruined it.

Sierra is an oily Pacific mackerel, firmer and more flavorful than tilapia or sea bass, and it cures into something unique under lime. Two hours minimum. The fish has to turn opaque all the way through. Then you squeeze it dry, because Mazatlan ceviche is mounded on a tostada, not served in a cup, and a wet ceviche slides off the shell.

I ate this for the first time on the malecon de Olas Altas, sitting on a plastic chair across from a senora who had been working the same marisqueria for thirty-one years. She would not give me the proportions for the carrot. She told me to come back the next day. I came back. Three days later, she wrote it on a napkin. Cada estado, su propia cocina. Sinaloa knows what it is doing.