Ancho chile: When fresh poblano chiles are dried, they’re called anchos. Mildly spicy, like their fresh counterparts, anchos give a rich sweetness to marinades or a simmering pot of chili.
Cilantro; This familiar Mexican herb is used only when fresh; it loses all flavor when dried. It provides an explosive sprinkle over lots of street foods, mostly as a component of salsa and guacamole. Store it wrapped in barely damp paper towels in a plastic bag, in the warmest part of the refrigerator.
Guajillo chile: These smooth-skinned, brick- or cranberry-red dried chiles are a little spicier than anchos, and not nearly as sweet. They’re often ground into a powder that gives a tangy jolt to fresh fruits and vegetables; teamed with anchos, they lend multilayered flavor to stews and soups.
Jicama; This root vegetable is the color of a potato, and not much bigger. Sliced or julienned, it adds a slightly sweet, juicy crunch to chicken salads or coleslaw. You can also peel it, slice it, and eat it as a snack, as Mexicans do.
Masa harina: Corn tortillas are made from dried grain (field) corn cooked with mineral lime, then ground into a paste called masa. Several decades ago, a method to dehydrate and powder the perishable masa was discovered; the result became known as masa harina, or masa flour.
Poblano chile: This mildly spicy, dark-green fresh chile resembles a small bell pepper, but with a pointed end, tougher skin, and more compact flesh. The flavor is also similar to that of a bell pepper, only more concentrated and complex.
Queso anejo: This hard, aged cheese, made from cow’s milk, adds a salty kick to whatever it touches. Dishes that always get a dusting of grated queso anejo, such as enchiladas, grilled corn on the cob, and street snacks made from corn masa, would be naked without it—like pasta without Romano or Parmesan.
Serrano chile: These bullet-shaped, hot green chiles are about 2×2 inches long and 1 1-2 inch wide. They have a punchy flavor that is heaven to green-chile lovers—much less sweet than a jalapeno.