Heat oven to 325° F.
Bring a pot of water boil, then remove pan from heat. Add the nopales and let them soak for about 5 minutes. Remove nopales from pan and put them on a paper towel to drain.
Put chorizo in sauté pan with olive oil and sauté on medium heat several minutes, until cooked through. Break into small pieces.
Place the cheese, nopales, chorizo and mushrooms in an oven-safe dish and bake for 10 to 15 minutes.
Garnish with avocado and serve with flour or corn tortillas, if desired.
Makes: 4