1 dozen large mushrooms (more or less depending on size)
3 tablespoons unsalted butter
2 tablespoons extra-virgin olive oil
2 teaspoons balsamic vinegar (or lemon juice)
2 teaspoons minced garlic
1 teaspoon fresh chopped thyme
Kosher salt and freshly ground black pepper, to taste
Instructions
Clean the mushrooms by briefly rinsing and gently wiping them with paper towels.
Combine the butter, olive oil, and garlic in a small saucepan; whisk in the balsamic vinegar and thyme and cook over medium-low heat for 2 to 3 minutes, until aromatic. Taste and add salt and pepper as desired.
Prepare the grill for medium-high heat.
Brush the mushrooms all over with some of the sauce mixture.
Grill the mushrooms, gill-sides down, for 4 minutes, basting again about halfway through. Flip, baste again with the sauce mixture, and grill for another 5 to 6 minutes or until tender.