Mix all of the ground spices together in a bowl. Set aside.

Trim the ends of the mushrooms and cut them in half. Working in batches, pulse in a food processor until roughly chopped—you want a coarse, crumbly texture, not a paste.

Bring a small pot of water to a boil. Add the guajillo chiles and boil for 2 minutes, then remove from heat and let steep in the hot water for at least 10 minutes until softened.

Drain and Blend the softened chiles with the raw onion and garlic until smooth. Make sure there aren’t chunks of guajillo. This can be done in the food processor, but if you want it to be very smooth, you can use a blender.

Heat the olive oil in a wide skillet over medium-high heat. Add the chopped mushrooms and cook, stirring occasionally, until most of their moisture has cooked off and they begin to brown.

Add the guajillo–onion–garlic mixture and cook for 5–10 minutes, stirring, until thickened and deeply red.

Stir in the spice mix and vinegar. Continue cooking until the mixture looks caramelized, rich, and slightly crispy at the edges. Lots of stirring needed to avoid burning - Add the ⅛ cup of oil to help with the sticking. Taste and adjust salt if needed.

Preheat the oven to 400°F. Add the cheese to a 9–10 inch cast-iron pan and bake until melted and bubbling.

Spoon the hot mushroom chorizo over the cheese and serve immediately with warm tortillas and salsa.