Various species grow on hard or soft wood logs. If you have access to fresh logs, this is a great way of turning dead space into a garden. These will produce 1-3lbs of shiitake per log per year. I got them for free when a redditor was cutting down a tree on their farm so it can be very low-cost high-yield.
I want to have a farm just so I can grow shrooms
That's the dream. Luckily they're easy to keep indoors but I really want to scale up and go professional.