Portobello Mushroom Sandwiches

Portobello mushrooms are wonderful for making substantial sandwiches for vegetarians and carnivores alike. Our portobello mushroom sandwich recipe enhances the mushroom caps with a delicious basil balsamic vinaigrette-style marinade, plus fresh sliced tomato and mozzarella cheese. Oh yeah, these are broiled, and the marinade even flavors the bread used to support the mushroom caps. Though this makes an open-faced sandwich, simply adding two more pieces of bread would turn them into a full, hearty handheld sandwich.

Ingredients for Portobello Mushroom Sandwiches

• Large portobello mushroom caps: Rinse the portobello mushrooms and remove their stems for this recipe.
• Olive oil: Olive oil is one of the ingredients in the lovely marinade for the mushrooms. Olive oil is more flavorful than other cooking oils, and it pairs well with balsamic vinegar.
• Balsamic vinegar: Balsamic vinegar adds a lovely somewhat sweet, somewhat sour flavor to the marinade, turning it into a simple version of a balsamic vinaigrette.
• Dried basil: This ingredient adds the flavor of basil to the marinade.
• Tomato: Four slices of tomato are all you’ll need for this recipe. Fresh heirloom tomatoes or large, juicy tomatoes from the garden or the farmers’ market are excellent choices.
• Mozzarella cheese: Choose sliced mozzarella for this recipe, as it’s easier to manage for sandwiches. If you have a ball of mozzarella, cut a couple of thin slices from it for the sandwiches.
• Italian bread: Two slices are all you’ll need for open-faced sandwiches; feel free to use four slices to make typical closed sandwiches. Choose 1-inch-thick Italian bread, as the thicker bread holds up best for these sandwiches.
• Chopped fresh basil:  hopped fresh basil adds a lovelyfresh herbal flavor to the sandwiches.

Directions

Step 1: Marinate the mushrooms

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Preheat the broiler. Place the mushrooms in a shallow bowl. Mix oil, vinegar, salt and dried basil together, then brush the mixture onto both sides of the mushrooms. Let them marinate for five minutes. Reserve the remaining marinade.

Step 2: Broil the mushrooms

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Place the mushrooms on a greased rack of a broiler pan, stem-side down. Broil the mushrooms 4 inches from the heat until they’re tender, three to four minutes per side. When the mushrooms are stem side up, top them with the tomato slices and cheese. Broil them until the cheese melts, about one minute.

Step 3: Broil the bread

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Place the bread on a baking sheet; brush it with the reserved marinade. Broil the bread 4 inches from the heat until the bread is lightly toasted, 45 to 60 seconds. Top the bread with the mushrooms. Sprinkle the mushrooms with chopped basil.

Editor’s Tip: If you’re using extra bread to make closed sandwiches, feel free to brush the marinade on those slices as well. Broil them along with the other bread slices.

Kristina Vänni for Taste of Home

Recipe Variations

• Add fresh basil leaves: Add a few basil or spinach leaves to the sandwich after broiling it for more flavor or nutrition. Basil brings the flavor, spinach brings vitamins A, C and K, plus potassium, iron and folate.
• Stuff those caps: Stuff the mushroom caps with a mixture of spinach, cream cheese, Parmesan cheese, garlic, salt and pepper, then broil them as directed. These are a cheese-lover’s dream! Here’s a similar recipe for broiled cheese-stuffed portobello mushrooms.
• Make them burger style: Use sturdy, thick hamburger buns such as onion buns or sesame seed buns for balsamic-flavored portobello mushroom sandwiches. Add fresh, crisp lettuce such as romaine or iceberg, plus onions, if desired.
• Add pesto: A basil-based pesto spread tastes extra delicious on these sandwiches. Serve the pesto alongside the sandwiches (or brush some on the top slice of bread if using two slices per sandwich).

How to Store Portobello Mushroom Sandwiches

Allow the broiled portobello mushrooms to cool to room temperature, then store them in airtight containers in the refrigerator, where they’ll keep for three to five days. It’s best to coat the bread and broil it just before enjoying the sandwiches. Feel free to reheat the mushrooms under the broiler as well, removing them when the cheese starts to bubble. The marinade will keep in the refrigerator for at least a week, so you can save it and use more when you assemble the sandwiches.

Can you freeze portobello mushroom sandwiches?

Yes, these can be frozen, but it’s best to freeze the broiled mushrooms separately from the bread so that the bread doesn’t get soggy. Place the mushrooms on a baking sheet and freeze them overnight or until they’re firm, then transfer them to airtight freezer containers. Freeze the bread plain (before broiling), or after broiling, but it will maintain the best flavor if you add the marinade and broil the bread just before enjoying the sandwich. Let the mushrooms and the bread thaw overnight in the refrigerator, then broil them until the cheese bubbles and the bread toasts. You’ll have to keep an eye on them if broiling both components at the same time, as the bread will be ready soonest.

Portobello Mushroom Sandwiches Tips

Kristina Vänni for Taste of Home

Could I make this in an air fryer instead?

Yes, you can make this dish in an air fryer. To make the air fryer version, marinate the mushrooms following this recipe. Preheat the air fryer to 400°F, then place the mushrooms stem-side down on a greased tray in the air-fryer basket. Cook until the mushrooms are tender, three to four minutes per side. Remove the mushrooms from the basket. With the stem side up, top the mushrooms with tomato and cheese; secure them with toothpicks. Place them back in the air fryer and cook them until the cheese melts, about one minute. Remove the mushrooms and keep them warm; discard the toothpicks. Place the bread on a tray in the air-fryer basket; brush the bread with the reserved marinade. Cook until the bread is lightly toasted, about two to three minutes. Top the bread with mushrooms. Sprinkle the sandwiches with chopped basil.

How can I make these vegan?

Make these sandwiches vegan by using a plant-based vegan mozzarella-style cheese, or a similar plant-based cheese that melts well. Though Italian bread is usually vegan, it’s best to read the ingredients before purchase just to be sure.

Could I use different bread?

Sure; choose a bread that won’t fall apart easily, and that’s thick enough to absorb some of the marinade. A sliced baguette works well, as do thick sourdough breads, hoagie buns or ciabatta rolls.