Preheat oven to 350 degrees F (175 degrees C). Spray a baking sheet with cooking spray. Clean mushrooms with a damp paper towel. Carefully break off stems. Chop stems extremely fine, discarding tough end of stems.
Heat oil in a large skillet over medium heat. Add garlic and chopped mushroom stems to the skillet. Fry until any moisture has disappeared, taking care not to burn garlic. Se