You can cultivate "chicken of the woods" fungus on certain wood mediums. This has decent flavor texture and protein content. It's a little fickle to cultivate

You can cultivate "chicken of the woods" fungus on certain wood mediums. This has decent flavor texture and protein content. It's a little fickle to cultivate and getting spores or plugs may be tricky. But this is probably your best bet at growing something similar to Quorn without a proper lab space.