Juicy, savory portobello mushrooms take center stage in this hearty vegan sub sandwich. Marinated, sautéed, and layered into a crusty Italian-style roll with crisp lettuce, fresh tomatoes, red onions, and melty plant-based cheese, this sandwich delivers classic deli satisfaction with a fully plant-based twist.
Why You’ll Love This Recipe
Big, meaty texture from portobello mushrooms makes it filling and satisfying
Completely plant-based yet rich and savory in flavor
Easy to customize with different vegetables or sauces
Perfect for lunch, dinner, or casual gatherings
Simple ingredients with bold Italian-inspired seasoning
Ingredients
(Tip: You’ll find the full list of ingredients and measurements in the recipe card below.)
For the mushroom filling
4 large portobello mushroom caps, cleaned and sliced into 1 cm thick strips
3 tablespoons olive oil
2 tablespoons balsamic vinegar
2 tablespoons soy sauce or tamari
2 cloves garlic, minced
1 teaspoon dried oregano
1 teaspoon dried basil
1/2 teaspoon smoked paprika
1/4 teaspoon black pepper
1/4 teaspoon salt
For the sandwiches
4 long vegan-friendly Italian sub rolls or demi-baguettes
1 teaspoon dried Italian herb blend for bread topping
1 tablespoon olive oil for brushing bread
120 g plant-based provolone or mozzarella-style cheese slices
2 cups romaine lettuce, shredded
2 medium red tomatoes, thinly sliced
1 small red onion, thinly sliced
Optional sauce
4 tablespoons vegan mayonnaise or dairy-free garlic sauce
Directions
In a large bowl, whisk together olive oil, balsamic vinegar, soy sauce, garlic, oregano, basil, smoked paprika, salt, and black pepper.
Add the sliced portobello mushrooms and toss gently until well coated. Let marinate for 10 minutes.
Heat a large skillet over medium-high heat. Add the mushrooms along with the marinade and cook for 8 to 10 minutes, stirring occasionally, until tender and lightly caramelized.
Preheat the oven to 180°C. Slice the sub rolls lengthwise without cutting all the way through.
Brush the inside of the rolls lightly with olive oil and sprinkle with dried Italian herbs.
Place the rolls on a baking tray, add vegan cheese slices inside, and warm in the oven for 5 minutes until slightly melted.
Remove from the oven and layer in the cooked mushrooms, romaine lettuce, tomato slices, and red onion.
Spread vegan mayonnaise or sauce if using, close the sandwich, and serve immediately.
Add roasted bell peppers or zucchini for extra vegetables
Use whole wheat or gluten-free rolls if preferred
Spice it up with chili flakes or a drizzle of hot sauce
Swap vegan cheese for a creamy hummus spread
Add sliced avocado for extra richness
Storage/Reheating
Store cooked mushrooms separately in an airtight container in the refrigerator for up to 3 days. Reheat mushrooms in a skillet over medium heat or in the microwave until warm. Assemble fresh sandwiches just before serving for best texture.
FAQs
Can I grill the mushrooms instead of sautéing them?
Yes, grilling adds a smoky flavor and works very well with portobello mushrooms.
What type of bread works best for this sandwich?
A crusty Italian sub roll or demi-baguette holds up best to the juicy filling.
Can I make this recipe oil-free?
You can reduce or omit the oil and sauté the mushrooms with a splash of vegetable broth instead.
Is this sandwich suitable for meal prep?
The mushrooms can be prepared ahead, but assemble the sandwich just before eating.
What vegan cheese melts best?
Plant-based provolone or mozzarella-style slices melt smoothly and complement the flavors.
Can I add a sauce other than vegan mayonnaise?
Yes, dairy-free pesto, garlic sauce, or mustard all work well.
Are portobello mushrooms nutritious?
They are low in calories and provide fiber, minerals, and a meaty texture.
Can I serve this sandwich cold?
It is best warm, but it can also be enjoyed cold like a deli sub.
How do I keep the bread from getting soggy?
Lightly toasting the bread helps create a barrier against moisture.
Can I make this sandwich gluten-free?
Yes, simply use gluten-free sub rolls.
Conclusion
This vegan portobello mushroom sub sandwich proves that plant-based meals can be bold, comforting, and incredibly satisfying. With its savory mushroom filling, fresh vegetables, and melty dairy-free cheese, it’s a recipe you’ll want to make again and again for quick meals or relaxed entertaining.
A hearty vegan sub sandwich featuring marinated and sautéed portobello mushrooms, fresh veggies, and melty plant-based cheese on a crusty roll, packed with bold Italian flavors.
Ingredients
4 large portobello mushroom caps, sliced into 1 cm thick strips
3 tablespoons olive oil
2 tablespoons balsamic vinegar
2 tablespoons soy sauce or tamari
2 cloves garlic, minced
1 teaspoon dried oregano
1 teaspoon dried basil
1/2 teaspoon smoked paprika
1/4 teaspoon black pepper
1/4 teaspoon salt
4 long vegan-friendly Italian sub rolls or demi-baguettes
1 teaspoon dried Italian herb blend
1 tablespoon olive oil (for brushing bread)
120 g plant-based provolone or mozzarella-style cheese slices
2 cups romaine lettuce, shredded
2 medium red tomatoes, thinly sliced
1 small red onion, thinly sliced
4 tablespoons vegan mayonnaise or dairy-free garlic sauce (optional)
Instructions
In a large bowl, whisk together olive oil, balsamic vinegar, soy sauce, garlic, oregano, basil, smoked paprika, salt, and black pepper.
Add the sliced mushrooms and toss gently until well coated. Let marinate for 10 minutes.
Heat a large skillet over medium-high heat. Add the mushrooms with the marinade and cook for 8–10 minutes, stirring occasionally, until tender and caramelized.
Preheat the oven to 180°C (350°F). Slice the sub rolls lengthwise without cutting all the way through.
Brush the inside of the rolls with olive oil and sprinkle with dried Italian herbs.
Place the rolls on a baking tray, add vegan cheese slices inside, and warm in the oven for about 5 minutes until cheese is slightly melted.
Remove from the oven and layer in the cooked mushrooms, shredded lettuce, tomato slices, and red onion.
Spread optional vegan mayo or garlic sauce on the inside of the roll, close the sandwich, and serve immediately.
Notes
Add roasted bell peppers or zucchini for more vegetables.
Use whole wheat or gluten-free rolls if desired.
Spice it up with chili flakes or hot sauce.
Swap vegan cheese for hummus for a different flavor profile.
Add sliced avocado for extra richness and creaminess.
