Easy Grilled Portobello Mushroom Sandwiches

Smoky grilled portobello mushroom sandwiches are my answer to cookout season — meaty caps, charred red onion rings, and sweet strips of yellow pepper stacked on toasted kaiser rolls with basil pesto. Scraping the gills out of the portobellos keeps everything tidy and full of flavor rather than dark and watery. These eat like a steak sandwich, no steak required.

Ready to level up your summer grilling game? Say hello to your new favorite sandwich! These Grilled Portobello Mushroom Sandwiches are packed with smoky, savory flavor and have a wonderfully ‘meaty’ texture that will satisfy everyone at the table. We’re piling tender grilled peppers, onions, and juicy tomatoes onto a toasted roll with a generous spread of zesty basil pesto. It’s simple, incredibly delicious, and proves that vegetarian grilling is anything but boring. Let’s get cooking!

Ingredients

• Serves: 4
• 4 large portobello mushroom caps, gills scraped out
• 1 large red onion, sliced into thick rings
• 1 large yellow bell pepper, sliced into strips
• 1-2 large ripe tomatoes, sliced
• 3 tablespoons (45 ml / 1.5 fl oz) extra-virgin olive oil
• Salt and freshly ground black pepper, to taste
• 3 tablespoons (45 ml / 1.5 fl oz) basil pesto, bottled or homemade
• 4 kaiser rolls or other hearty sandwich rolls

Instructions

1. Preheat your grill to medium-high heat.
2. In a large bowl, toss the portobello caps, sliced onion, and bell pepper with the olive oil. Season generously with salt and pepper.
3. Place the vegetables on the grill. A mesh grill basket is perfect for preventing the smaller pieces from falling through. Grill, turning once, until tender and slightly charred, about 8-10 minutes.
4. During the last 2 minutes of cooking, lightly brush the tomato slices with oil and grill them for about 30-60 seconds per side, just until they have light grill marks.
5. To assemble, spread about 2 teaspoons (10 ml / 0.3 fl oz) of pesto onto each roll. Layer with the grilled portobello mushroom, peppers, onions, and tomato slices.
6. Serve immediately while hot.

Nutritional Information

• (per serving)
• Calories: 450 kcal
• Protein: 12 g
• Carbohydrates: 55 g
• Fat: 20 g
• Fiber: 8 g

Pro Tips

• Use a mesh or perforated grill basket to prevent the sliced onions and peppers from falling through the grates.
• No grill? You can broil the vegetables on a sheet pan or sear them in a hot cast-iron skillet until tender and charred.
• For extra flavor, marinate the portobello mushrooms in a little balsamic vinegar, olive oil, and garlic for 30 minutes before grilling.
• Lightly toast the rolls on the grill for the last minute of cooking to add extra texture and warmth.

FAQ

Q: Can I make this portobello sandwich vegan
A: Absolutely! To make this sandwich vegan, simply use a dairy-free basil pesto (many store-bought versions are available, or you can make your own without parmesan cheese) and ensure your sandwich rolls are free from eggs or dairy.

Q: How can I add more protein to this vegetarian sandwich
A: For a protein boost, consider adding a slice of provolone or mozzarella cheese during the last minute of grilling. You could also spread a layer of hummus or white bean dip on the roll, or serve the sandwich alongside a quinoa salad.

Q: How should I store leftover grilled vegetables
A: Store any leftover grilled mushrooms, peppers, and onions in an airtight container in the refrigerator for up to 3 days. For best results, reheat them in a skillet, air fryer, or on the grill before assembling a fresh sandwich to avoid soggy bread.

Q: Do I have to scrape the gills out of portobello mushrooms
A: While you can eat the gills, we recommend scraping them out with a spoon. They can release a dark, sometimes muddy-tasting liquid during cooking, which can discolor the other ingredients and affect the overall flavor of your sandwich.

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Stav Kogan

Grilled Portobello Mushroom Sandwiches

Packed with smoky, savory flavor, these Grilled Portobello Mushroom Sandwiches have a wonderfully 'meaty' texture. We're piling tender grilled peppers, onions, and juicy tomatoes onto a toasted roll with a generous spread of zesty basil pesto. It's simple, incredibly delicious, a

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Servings: 4 servings

Calories: 450

Ingredients Method Nutrition

Ingredients

  

1x2x3x?

• 4 large portobello mushroom caps, gills scraped out
• 1 large red onion, sliced into thick rings
• 1 large yellow bell pepper, sliced into strips
• 1-2 large ripe tomatoes, sliced
• 3 tablespoons (45 ml / 1.5 fl oz) extra-virgin olive oil
• Salt and freshly ground black pepper, to taste
• 3 tablespoons (45 ml / 1.5 fl oz) basil pesto, bottled or homemade
• 4 kaiser rolls or other hearty sandwich rolls
• Use a mesh or perforated grill basket to prevent the sliced onions and peppers from falling through the grates.
• No grill? You can broil the vegetables on a sheet pan or sear them in a hot cast-iron skillet until tender and charred.
• For extra flavor, marinate the portobello mushrooms in a little balsamic vinegar, olive oil, and garlic for 30 minutes before grilling.
• Lightly toast the rolls on the grill for the last minute of cooking to add extra texture and warmth.

Method

 

1. Preheat your grill to medium-high heat.
2. In a large bowl, toss the portobello caps, sliced onion, and bell pepper with the olive oil.
3. Season generously with salt and pepper.
4. Place the vegetables on the grill. A mesh grill basket is perfect for preventing the smaller pieces from falling through.
5. Grill, turning once, until tender and slightly charred, about 8-10 minutes.
6. During the last 2 minutes of cooking, lightly brush the tomato slices with oil and grill them for about 30-60 seconds per side, just until they have light grill marks.
7. To assemble, spread about 2 teaspoons (10 ml / 0.3 fl oz) of pesto onto each roll.
8. Layer with the grilled portobello mushroom, peppers, onions, and tomato slices.
9. Serve immediately while hot.

Nutrition

Calories: 450kcalCarbohydrates: 55gProtein: 12gFat: 20g

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