I asked my mom. she said "oh that's 猴頭菇" which translates to monkey head mushroom.

I asked how she prepares it and she said "those are kind of a pain in the ass"

here's her recommendation...

shred them by hand only. do not cut with knife.

use it to make a light brothy soup. can have it by itself or use it in other dishes.

After shredding, can be stir fried like any shredded chicken dish.