TUCSON — There are food deserts, those urban neighborhoods where finding healthful food is nearly impossible, and then there is Tucson.

When the rain comes down hard on a hot summer afternoon here, locals start acting like Cindy Lou Who on Christmas morning. They turn their faces to the sky and celebrate with prickly pear margaritas. When you get only 12 inches of rain a year, every drop matters.

Coaxing a vibrant food culture from this land of heat and cactuses an hour’s drive north of the Mexican border seems an exhausting and impossible quest. But it’s never a good idea to underestimate a desert rat. Tucson, it turns out, is a muscular food town.