Shroom Sandwich Recipe

Prepare marinade

In a shallow dish or bowl, whisk together 3 tbs olive oil, 2 tbs balsamic vinegar, 1 tbs soy sauce, minced garlic, dried oregano, 1 tsp salt, and 1/2 tsp freshly ground black pepper until combined.

Clean mushrooms

Gently wipe the portobello caps with a damp paper towel to remove dirt. Remove and discard stems. If desired, scrape out the dark gills with a spoon for a milder flavor.

Marinate

Place the mushroom caps gill-side down in the marinade and spoon some over the tops. Let marinate at room temperature for 15–20 minutes, turning once so both sides absorb marinade. Reserve marinade.

Grill or pan-sear

Heat a grill or large nonstick/skillet over medium-high heat. If using a skillet, add 1 tbs olive oil and heat until shimmering. Place mushrooms gill-side down first, cook 4–5 minutes until nicely browned, then flip and cook another 3–4 minutes, brushing with reserved marinade. Mushrooms should be tender and slightly caramelized. Remove from heat and let rest 2 minutes; slice if desired or leave whole to fit bread.

Make pesto

In a food processor or blender combine 1 cup packed basil leaves, 2 tbs pine nuts, 1 clove garlic, 1/4 cup grated parmesan, 3 tbs olive oil, 1/2 tsp lemon juice, 1/4 tsp salt, and a pinch (1/8 tsp) black pepper. Pulse until a coarse, spreadable paste forms. Scrape down sides and pulse once more. Taste and adjust salt or oil to reach a spreadable consistency.

Toast bread (optional)

If you prefer toasted bread, lightly butter one side of each bread slice. Heat a skillet over medium heat and toast buttered side down 1–2 minutes until golden. Alternatively, toast bread in a toaster.

Assemble sandwiches

Spread about 1 to 1 1/2 tbs pesto on the non-buttered side of each of two bread slices. Place one grilled portobello cap (or slices) on each pesto-coated slice. Top each mushroom with one slice provolone; if you want the cheese melted, return sandwich halves (open-faced) to the warm skillet for 30–60 seconds until the cheese softens. Season the mushrooms lightly with a pinch of salt and 1/8 tsp black pepper.

Add greens and finish

Place 1/2 cup mixed greens on top of the cheese on each sandwich. Close sandwiches with the remaining bread slices, pesto side in. Press gently, slice in half if desired, and serve immediately.