In a large mixing bowl, combine the quartered mushrooms with extra-virgin olive oil, ensuring each piece is lightly coated. Season generously with kosher salt and a few grinds of freshly ground black pepper, tossing well to distribute the flavors evenly.

Place a large skillet over medium heat and add the butter. As it melts and begins to foam, stir in the minced garlic. Sauté the garlic for about 30 seconds, just until fragrant, being careful not to let it brown.

Immediately add the mushrooms to the skillet, tossing them gently to ensure they are evenly coated in the butter and garlic mixture. Let them cook undisturbed for about 2 minutes, allowing the edges to develop a rich, golden-brown sear. Continue cooking for 10-12 minutes, stirring every couple of minutes to promote even caramelization and deepen their savory flavor.

Once tender and deeply golden, remove from heat and sprinkle with freshly chopped parsley. Serve warm as a flavorful side dish or a delicious topping for meats, pasta, or grains.