Dry-roast the tomatoes, chilies and garlic on a comal or skillet set over medium heat. Remove the garlic when brown spots appear on the papery skin, then peel and reserve.

Keep turning the tomatoes and chilies as they char. Discard the stem of the chilies.

Place the tomatoes, chilies and garlic in a blender, season with salt and blend. The sauce should be thick.

Heat the oil in a sauté pan, add the onion and chilies and sauté for 2 to 3 minutes until translucent. Add the garlic and sauté for 1 minute, then mix in the mushrooms, reduce the heat to simmer and cover with a lid.

Cook for 5 to 8 minutes until the mushrooms are cooked through. Add the epazote and move the pan off the heat.

Place 4 tortillas on a flat surface. Using half of the cheese, make a thin layer on top of each tortilla. Divide the mushroom filling among the 4 tortillas and top with an even layer of the remaining cheese. Cover each with one of the remaining tortillas.

Heat a comal or a griddle over medium-low heat. Place the sincronizadas (tortilla sandwiches) on top—pressing down with a spatula as they cook.

The tortillas should have some brown spots and be slightly crispy, while the filling should be warm and the cheese melted.

Cut them in half, or not, and serve warm with the salsa on the side.