Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper for easy cleanup.

Prepare the mushrooms: If needed, gently clean the mushrooms with a damp paper towel. Trim the stems but keep the mushrooms whole for a better roasted texture.

Make the garlic butter sauce: In a small bowl, combine melted butter, olive oil, minced garlic, salt, and pepper. Mix well until the garlic is evenly distributed.

Toss the mushrooms: Place the mushrooms in a large mixing bowl. Pour the garlic butter mixture over them, tossing the mushrooms until they are well-coated.

Roast the mushrooms: Spread the mushrooms out in a single layer on the prepared baking sheet. Roast in the preheated oven for 20–25 minutes, or until the mushrooms are tender and caramelized, stirring once halfway through the cooking time.

Finish with herbs: Remove the mushrooms from the oven and immediately toss them with freshly chopped parsley or your preferred herbs. Serve hot.