In order to cook the Lion's Mane mushroom correctly and is really one mane thing you need to do correctly.
The Lions Mane mushroom is a member of the Tooth fungus and has many long strands that look like tentacles or strands of hair. This is what makes it a little more challenging to cook.
This biggest challenge is because of all the long strands it can soak up a lot of water which can destroy your attempt to cook it if you don't soak up as much of that water as you can.
The good news is once you soak up all that water you can saute it, deep fry it or eat it raw just like you do any other mushroom.
Check out a video I made of me cooking the Lion's Mane mushroom. I saute it and deep fry it here as well as list the recipe I used:
https://curativemushrooms.com/how-to-cook-lions-mane-mushroom-simplest-lobster-recipe