Lay a piece of aluminum foil on the bottom of a cast-iron skillet (for easier cleanup, as juices have a tendency to weep and scorch the pan) and set it over medium heat. Place the ancho chile on the foil and cook about 2 minutes, turning once, until the chile smells toasty.

Remove the chile and set aside, then add the onion and garlic and cook 10-15 minutes, turning the vegetables once or twice as they brown. Or place the vegetables on a baking sheet under a broiler and cook 6-7 minutes, turning them once halfway through the cooking process.

Discard the stem and seeds from the cooled chile and tear it into pieces.

Place the chile in a small bowl, cover with hot water, and add the vinegar. Let it soak for about 10 minutes.

Peel the garlic cloves and place them in a food processor or blender along with the onions.

Char the tomatoes in the same pan on the foil or under the broiler, turning several times so they are evenly blistered, about 10 minutes.

Chop the tomatoes (skin and all) and add to the food processor.

Save the chile soaking liquid and add the pieces of chile. Pulse to blend the sauce thoroughly. If necessary, add a little of the chile liquid to thin the sauce (it should have the consistency of thick tomato juice).

Season to taste with salt. Heat the olive oil in a medium saucepan and carefully pour in the sauce. Cook, stirring, over medium-high heat for about 10 minutes. The sauce will darken and thicken a little.

Add some water or, preferably, Chicken or Vegetable Stock to adjust the consistency.

Simmer gently for about 5 more minutes and adjust the seasoning to taste. Hold the sauce at room temperature while you make the vegetable filling. (Alternatively, the sauce can be made a day in advance.)

Heat 1 tablespoon oil in a large skillet over medium-high heat. When the pan is very hot but not smoking, add the onion and poblano and toss to coat evenly with oil.

Cook for 4-5 minutes, then scrape the vegetables into a large bowl and return the skillet to the heat. Heat another tablespoon of the oil; add the mushrooms and cook, tossing or stirring, until they are wilted and starting to get brown and crispy, 3-4 minutes. Stir in the oregano and coriander. Season with a little salt and add to the bowl of vegetables. Heat the remaining tablespoon of oil, toss in the zucchini pieces, and cook for 4-5 minutes, or until tender. Season with salt, stir in the scallions, and scrape the zucchini into the bowl with the other vegetables. Grind a little black pepper over the vegetables and stir in the cilantro.

Preheat the oven to 350°F.

Use a pastry brush to grease a 13 × 9-inch baking pan or shallow oblong baking dish with vegetable oil.

Ladle about ½ cup of the sauce into the bottom of the greased pan and spread evenly.

Place about half the remaining sauce in a 10-inch skillet and warm gently. Submerge one tortilla in the sauce and let it warm until it is soft and pliable (about 5-10 seconds), then lift it out, draining the excess sauce back into the skillet. Place the tortilla on a work surface, spoon on about 3 tablespoons of the vegetable mixture, sprinkle with a little cheese, and roll it up into a snug cylinder.

Place the enchilada seam side down in the baking pan. Fill more tortillas in the same manner. They should fit snugly in the pan, in one layer.

Pour the rest of the sauce over the enchiladas and sprinkle with the remaining cheese.

Bake for about 15 minutes, until they are hot all the way through and the cheese is bubbly. Garnish with onion, cilantro, and jalapeños and serve.