Melt 1 1/3 tablespoons butter with olive oil in a large saucepan over medium-high heat; add mushrooms. Cook, stirring often, until edges browned, 15 to 20 minutes.
2
Preheat the oven to 350 degrees F (175 degrees C).
3
Combine 2 teaspoons softened butter and garlic in a small bowl. Grease a 9x13-inch baking dish with garlic butter.
