@sjw
A lazy solution might be a cheap hydroponics kit (minus the light) from Amazon, and that's plenty of space for small batches.
I don't know about everywhere else, but it's legal here to grow and consume; spores are easy to get.
A quick glance tells me this page is a good starting point: https://hydrobuilder.com/learn/hydroponic-mushrooms/
Here's a little something I grew, and the teriyaki chicken I made for dinner for scale.
GNU social JP is a social network, courtesy of GNU social JP管理人. It runs on GNU social, version 2.0.2-dev, available under the GNU Affero General Public License.
All GNU social JP content and data are available under the Creative Commons Attribution 3.0 license.