Quesadilla de Hongos

The mushrooms have to be cooked twice as long as instinct says before they ever reach the tortilla. Sliced raw champiñones go into a hot pan with chopped white onion and garlic, and at first they steam, throwing off a pool of their own water. A cook who stops there folds a wet gray tangle into the masa and the seam will not seal. The good version pushes past the steam to the point where the pan goes dry and the mushroom edges begin to color and catch, the flavor turning from watery to deep and browned. A handful of torn epazote goes in at the end, the reduced mushrooms go onto a fresh corn tortilla with a scatter of quesillo, and the fold is pressed to the comal until the inside fuses.

What the dairy contributes is the part the mushroom cannot supply itself. Cooked-down fungi bring an earthy, almost meaty savor and a soft chew, but no fat, no salt, and nothing sticky enough to hold a loose pile together. The melted cheese is the fat and the glue at once, turning a heap of browned slices into one cohesive bite that pulls in a pale thread when the halves are drawn apart. Run the ratio wrong and the build fails in two familiar directions: too much cheese and the mushrooms vanish into a salty melt, too little and the filling tumbles out the open end as the cook lifts the wedge off the steel.

Lean over a finished one and the smell is browned mushroom over toasted masa, a low woodsy savor with the green snap of epazote cutting across it. The masa has gone freckled and faintly crisp at the edge, crackling as the fold is bent. Inside, the mushrooms have a yielding, slightly springy give, dense and dark where the raw slices were pale, bound in a soft melt that strings briefly toward the lip. It eats the way a soft meat filling eats, savory and substantial, except there is no meat in it and never was, which is the small surprise the dish is built to deliver.

Mushroom quesadillas belong to the cooler, wetter half of the central-Mexican year, when rain pushes wild fungi up under the pines and the markets fill with hongos silvestres the rest of the season never sees. At Mercado San Juan in Mexico City, stalls fill in July and August with wild types sourced from the forests of Tlaxcala, Puebla, and Oaxaca, traded mostly by women from the highland villages who know the calendar by the look of the forest floor. A comal cook in the market will sell a champiñon fold year round from cultivated stock, but in those months the same stall may offer foraged types alongside it, sold by weight from baskets a few paces over. The seasonal wild version commands a little more and tastes of more.

The mushroom fold sits beside the other earthy vegetable quesadillas of the highlands, nearest to the corn-fungus huitlacoche, which pushes the same dark savor toward something inkier and closer to truffle, and across from the floral, gentle squash-blossom version that asks for restraint instead of reduction. Wild types like the apricot-scented tejamanil or trumpet-shaped corneta shift the flavor when the season offers them, but the long dry sautee with onion and epazote holds across all of them.

Mushrooms in the highland kitchen

Foraging wild mushrooms is one of the oldest food practices in central Mexico, carried unbroken from the pre-Hispanic kitchen into the present. The highland states of México, Puebla, Tlaxcala, and Morelos hold long traditions of gathering dozens of edible species from the pine forests in the rainy season, knowledge passed down in the villages that supply the city markets. The Nahua and Matlatzinca communities of the valley around Toluca are among those credited with the deepest field knowledge, though no single origin for the comal preparation has ever been documented.

The cultivated mushroom is the newcomer in the pan. Commercial cultivation of Agaricus bisporus began in Mexico in 1933, by most accounts, and took until roughly 1955 to grow into stable, dependable production. That arrival split the dish in two streams that now sit side by side at the same comal: the wild-gathered tradition that reaches back to the pre-Hispanic kitchen and the farmed button mushroom that arrived in the twentieth century and made the fold a year-round proposition. The wild version is still a creature of the rains, made from whatever the highland forests give up between roughly June and September; the cultivated one has stayed on the comal every month since the growers of the 1930s finally made it reliable.