Grilled Portabella Recipe

Clean and prepare mushrooms

Wipe the portabella caps clean with a damp paper towel. Remove and discard stems. If you prefer, gently scrape out the dark gills with a spoon to create a smoother surface for topping (optional).

Make marinade

In a small bowl whisk together 3 tablespoons olive oil, apple cider vinegar, minced garlic, dried oregano, kosher salt, and black pepper until combined.

Place the mushroom caps gill-side up in a shallow dish or rimmed baking sheet. Spoon or brush half of the marinade over the gill surface and the remaining half on the outside/cap. Let marinate at room temperature for 15 minutes, turning once to coat evenly.

Preheat a gas grill or grill pan to medium-high (about 400°F / 200°C). Lightly oil the grate or brush mushrooms with a touch more olive oil if surface looks dry.

Grill the mushrooms, gill-side down first, for 4–5 minutes, then flip and grill gill-side up for another 4–6 minutes, basting once with reserved marinade, until tender and slightly charred. Total grilling time ~8–11 minutes depending on thickness. Remove from grill and set on a platter.

Prepare topping

While mushrooms are marinating or grilling, combine the diced roma tomatoes, diced red bell pepper, sliced basil, optional finely diced red onion, lemon juice, 1 teaspoon olive oil, 1/4 teaspoon salt and 1/8 teaspoon black pepper in a bowl. Toss gently to combine and let sit for 5–10 minutes to allow flavors to meld.

Taste and adjust seasoning with additional salt or lemon if needed.

When mushrooms are finished on the grill, spoon the tomato and pepper mixture evenly over the two mushroom caps, distributing juices but draining excess liquid if very wet so mushrooms don't become soggy.

Make balsamic glaze

In a small saucepan combine 1/4 cup balsamic vinegar and 1 tablespoon brown sugar (or honey) with a pinch of salt. Bring to a gentle simmer over medium-low heat and cook, stirring occasionally, until reduced and syrupy, about 6–8 minutes. The glaze should coat the back of a spoon. Remove from heat and let cool slightly; it will thicken further as it cools.

Drizzle the warm balsamic glaze over the topped portabella caps in a thin ribbon. Garnish with chopped parsley (if using) and an extra tear of basil leaves for color.

Serve immediately while warm as an appetizer. If preparing ahead, keep glaze at room temperature and rewarm gently; do not soak mushrooms — assemble just before serving.