Prepare the mushrooms: Clean and slice mushrooms if not pre-sliced. Pat them dry to remove excess moisture.
Heat the pan: Place a large skillet over medium heat. Add olive oil or butter and allow it to heat until shimmering or melted.
Cook the mushrooms: Add mushrooms to the pan in a single layer. Let them cook undisturbed for 5-7 minutes until golden brown on one side.
Stir in garlic and herbs: Flip the mushrooms and stir in the minced garlic and thyme. Cook for another 3-5 minutes until fragrant and mushrooms are tender.
Season and serve: Sprinkle with salt, black pepper, and chopped parsley. Serve immediately as a side dish or topping for toast, steak, or pasta.