Step 1
Set the oven’s temperature to 375°F (190°C). A baking sheet may be gently greased with cooking spray or lined with parchment paper.
Step 2
Carefully cut the mushroom stems off and save them. To remove any dirt or debris, clean the mushroom tops with a moist paper towel. Place the cleaned mushroom caps stem-side up on the prepared baking sheet.
Step 3
Chop the saved mushroom stems into a fine powder.
Step 4