Sauté mushrooms in olive oil until al dente. Set aside.
For Anaheim Chile Cheese Filling
Broil the chilies in the oven until skins are black and blistered. Place in a baggie for 30 minutes to steam. Remove skins and seeds. Chop into 2 inch strips.
For All Tamales
Spread masa in a thin layer onto a corn husk. Add cheese and rest of filling. Roll and fold end up and secure. Place in steamer.
Add a layer of corn husks on top of the tamales and put the lid on. Steam for an hour or until done.