01 - Set your grill or grill pan to medium-high heat and allow it to fully preheat.
02 - In a large bowl, toss the cleaned mushrooms with 1½ tbsp olive oil, a generous pinch of salt, and freshly ground black pepper until evenly coated.
03 - Thread the 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 have light char marks.
05 - Heat the remaining 1½ tbsp olive oil in a large skillet over medium heat. Add the minced garlic and cook for about 30 seconds until fragrant, stirring constantly to prevent burning.
06 - Add the grilled mushrooms to the skillet along with the thyme and half of the chopped parsley. Sauté for 2 to 3 minutes, gently stirring, until the mushrooms are glistening and evenly coated with the garlic oil.
07 - Taste and adjust with additional salt and black pepper as needed.
08 - Transfer to a warm serving dish and garnish with the remaining parsley. Sprinkle with grated Parmesan cheese if desired.