Heat oil in a large non-stick skillet over medium-high heat
Once the oil is hot, add the mushrooms and fry, stirring occasionally. The mushrooms will begin to release liquid, so you will want to continue cooking these until most of the liquid is cooked off, about 10-12 minutes.
Once most of the liquid is gone, add the onions, garlic, and chiles. Continue to fry, stirring occasionally until the mushrooms and garlic begin to brown, about 5 minutes
Add the epazote and stir to incorporate, cooking an additional 1-2 minutes or until the mushrooms are browned to your liking.
Add salt to taste, stir to incorporate, and remove the mushrooms from the heat.
Heat a comal or skillet over medium high heat
Place a tortilla on the comal and heat on one side until warmed through, about 30-60 seconds
Flip the tortilla and place 1/4 of the cheese on half of the tortilla and 1/4 of the mushrooms on top of the cheese. Fold the empty side of the tortilla over the filling.
Heat until the cheese is melted, flipping over halfway through cooking, about 2 1/2 minutes per side.
Serve immediately