Preheat oven to 300F.
Put baby kale on parchment lined baking sheet. Spray with cooking spray and mix with your hands to ensure all is coated.
Bake for 10 minutes, then gentley toss spreading out on baking sheet. Bake for an additional 5 minutes or until all pieces crispy. Remove from oven and set aside.
Heat 2 tbsp butter in sauce pan over medium heat. Add all mushrooms except shimeji. Do not move around or shake, just let them be.
After a few minutes give the pan a shake to toss the mushrooms and try to flip as many as possible to ensure even browning. Add 1 tbsp of butter, a sprinkle of black pepper, salt and some fresh thyme. Once browned on all sides remove to a bowl.
Add 1 tbsp of butter to sauce pan and shimeji mushrooms if using. Follow same guidelines as above. Add remaining 1 tbsp of butter, toss around and add to bowl of mushrooms.
On toast add two slices of brie cheese, mushrooms and top with crispy kale chips. Serve immediately.