When it comes to grilling mushroom I would have to say that Portobello mushroom are king. Nice and meaty these mushrooms eat like a steak. The key to this recipe is mushroom tenderness. You don’t have to rush it. Tender is better than undercooked.
Medium high 450-550°F
6 medium Portobello mushroom caps, about 3-4 inches in diameter
3 cups hot water
3 tbsp extra virgin olive oil
1/3 cup aged balsamic vinegar
6 cloves garlic, minced
1 tbsp chopped fresh oregano
Pinch red pepper flakes
Kosher Salt and freshly ground black pepper to taste
¼ cup grated parmesan cheese
½ cup crumble gorgonzola cheese
½ cup Panko breadcrumbs
1 cup shredded mozzarella cheese
Brush any dirt off the mushrooms and cut off and discard the stems. Put the mushroom caps in a large bowl and cover with the hot water; let stand for 10 to 15 minutes to allow the mushrooms to soften. Drain and pat dry on paper towels.
In the same bowl, mix together the olive oil, balsamic vinegar, garlic, oregano and red pepper flakes. Season to taste with kosher salt and freshly ground black pepper. Add mushroom caps, turning to coat well, and let marinate while you prepare the stuffing. Give the mushrooms a good amount of time to marinate. In this case at least 30 minutes.
In a bowl stir together the parmesan, gorgonzola, breadcrumbs and mozzarella cheese.
Grill the mushrooms gill side down for 6-8 minutes or until slightly charred and just tender. Lid open to keep an eye open for flare ups.
Turn mushrooms over and sprinkle the cheese breadcrumb mixture evenly over the gill side of the mushroom. Close the lid and cook for 7 to 8 more minutes or until the cheese is hot and bubbling
Remove from grill, drizzle with a little more aged balsamic vinegar and serve immediately.