Wipe mushrooms with a damp cloth and trim bottoms of stems. Slice mushrooms about 1/4 inch thick.
In a 12-inch skillet, heat olive oil over medium-high heat. Add garlic, saute until lightly golden and discard with a slotted spoon. Add mushrooms; quickly toss with a wooden spoon until mushrooms are well coated with olive oil. Cook, stirring constantly, just until mushrooms begin to exude their juices, about 1 minute.
Add breadcrumbs and quickly toss with mushrooms until no liquid is left in pan. Season with salt and pepper; remove from heat.
Add parsley and mix lightly just to incorporate. Transfer to a small platter and serve immediately.