First, prepare the mushrooms. Start by gently wiping the portobello mushrooms with a damp paper towel to remove any dirt. Next, remove the stems and, if you prefer, scrape out the gills using a spoon. The gills are edible, but some people find them too strong in flavor.
Now, let’s make the marinade. In a small bowl, mix the olive oil, balsamic vinegar, minced garlic, dried thyme, and dried rosemary. Place the mushrooms in a shallow dish, gill-side up, and pour the marinade over them. Use a brush or spoon to ensure the marinade covers all surfaces.
While the mushrooms marinate, preheat your grill to medium-high heat. If you’re using a charcoal grill, ensure the coals are evenly distributed to provide consistent heat.
For a gas grill, preheat it to around 375°F (190°C). Proper preheating ensures even cooking and helps achieve the desired texture and flavor.
Once the grill is ready, place the marinated mushrooms on the grill, gill-side down. Close the lid and grill for about 5–7 minutes. Then, flip the mushrooms and grill for another 5–7 minutes. You want the mushrooms to be tender and have beautiful grill marks.
