Portobello Mushroom Recipe

Prepare and roast mushrooms

Preheat oven to 425°F (220°C). Clean portobello caps by wiping with a damp cloth and remove stems. Gently scrape out the gills if you prefer less moisture. Place mushrooms on a rimmed baking sheet, gill-side up. In a small bowl, combine 2 tbs olive oil, minced garlic, balsamic vinegar, 1 tsp salt and 1/2 tsp black pepper. Brush or spoon the mixture evenly over the mushroom caps. Roast in the preheated oven for 12–15 minutes until tender and juices begin to release.

Wilt spinach

While mushrooms roast, heat a medium skillet over medium heat. Add a light drizzle (about 1/2 tbs) of olive oil. Add the baby spinach and sauté, stirring, until just wilted, about 2–3 minutes. Season with a pinch of salt and the optional 1 tsp lemon juice. Remove from heat and set aside, patting lightly to remove excess moisture if needed.

Slice tomato

Thinly slice the tomato into 6–8 slices. Pat slices dry with a paper towel to avoid extra moisture on the flatbread.

When mushrooms have about 4 minutes left in the oven, remove the tray briefly and top each roasted portobello with one slice of Swiss cheese (or vegan substitute). Return to the oven for the remaining 4 minutes to melt the cheese and finish roasting the mushrooms. Alternatively, you can melt cheese under the broiler for 1–2 minutes—watch carefully to avoid burning.

Spread 1 tsp pesto and 1 tsp mayonnaise on each flatbread. If making vegan, use the vegan pesto and vegan mayonnaise substitutes in the same quantities.

Warm the flatbreads: Lightly brush both sides of each flatbread with butter or olive oil (about 1/2 tsp per side). Warm in a dry skillet over medium heat for 30–45 seconds per side until pliable and slightly toasted, or warm in a 350°F (175°C) oven for 4–5 minutes.

Assemble the flatbread: Place each warmed flatbread on a work surface. Spread the pesto and mayo (already applied) across the center. Place one cheese-topped portobello cap in the middle of each flatbread, cheese-side up. Add an even handful (about 1 cup) of wilted spinach on top of the mushroom, then layer 2–3 tomato slices per flatbread. Season tomato with a small pinch of salt and a grind of black pepper if desired.

Finish and serve: Garnish with fresh basil leaves if using. Fold the flatbread slightly or serve open-faced. Serve immediately while warm.