01 - Set a grill or grill pan to medium-high heat and allow it to come to temperature.
02 - In a large bowl, toss the mushrooms with 1½ tbsp olive oil, salt, and black pepper until evenly coated.
03 - Thread the seasoned mushrooms onto skewers or place them in a grilling basket to prevent them from falling through the grates.
04 - Grill for 6 to 8 minutes, turning occasionally, until the mushrooms are tender and lightly charred.
05 - Heat the remaining olive oil in a large skillet over medium heat. Add the minced garlic and cook for 30 seconds until fragrant.
06 - Add the grilled mushrooms, thyme, and half the parsley to the skillet. Sauté for 2 to 3 minutes, stirring gently, until the mushrooms are glistening and well coated.
07 - Taste and adjust with additional salt and pepper as needed.
08 - Transfer to a serving dish and garnish with the remaining parsley and Parmesan cheese if using.