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 and shrinking to a third of their volume. A cook who stops there folds a wet gray tangle into the masa and the fold 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 it the wrong way 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.

The whole technique is a fight with water, won at the stove rather than the fold. Mushrooms left under-cooked dump liquid into the masa, the seam refuses to bond, and the quesadilla weeps from its open side on the first bite. Sauteed too timidly they stay pale and taste of nothing in particular, the browning that makes them savory never developed. The epazote is structural seasoning here as much as flavor: its sharp herbal edge keeps the deep mushroom note from sliding into something flat and muddy. Folding hot filling onto a cold tortilla fails in its own way, the masa cracking at the crease and the cheese never reaching a clean melt.

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 and watery, 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. A comal cook in a Mexico City market will sell a champiñon fold year round from cultivated stock, but in the rainy months the same stall may offer foraged types alongside it, sold by weight from baskets a few stalls over. The seasonal wild mushroom version commands a little more and tastes of more, and the people who know the calendar wait for it the way they wait for the corn fungus that shares the season.

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. A mushroom fold that has swapped the fungus for shredded chicken or chorizo has left this dish behind for a meatier one.

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 cultivated mushroom is the newcomer in the pan. The fold has no inventor and no founding date of its own, a folk preparation rather than an authored one, but the button champiñon that lets a stall sell it in any month carries a precise one. Commercial cultivation of Agaricus bisporus began in Mexico in 1933 and took until about 1955 to grow into stable, dependable production, the early growers spending two decades overcoming the difficulty of farming a fungus.

That date is what split the dish in two. The two streams 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 that arrived in the twentieth century. 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 of the year since the growers of 1933 finally made it dependable.