You’ll never miss the meat in these hearty and satisfying Portobello Mushroom and Spinach Subs. They’re a delicious weeknight dinner and prepared in just 30 minutes from start to finish!
If you’re a mushroom lover, you’re going to want to devour this savory sandwich. The marinade is a zesty and flavorful combination of red wine vinegar, Worcestershire sauce, spicy mustard, garlic, and olive oil. HEAVENLY.
- Portobello mushrooms – wiped clean and debris removed with a damp towel, then cut into about 2-inch pieces.
- Red onion – thinly sliced
- Baby spinach – roughly chopped
- Spicy mustard
- Olive oil
- Red wine vinegar
- Worcestershire sauce
- Salt and black pepper
- French baguette loaf – you can also use toasted bread, hamburger buns or sub rolls in place of the baguette… I love the texture of the crunchy baguette.
- Shredded mozzarella – finely shredded Parmesan would be delicious, as well!
How to Prepare
Following is a brief overview of how to prepare – please see the recipe card at the bottom for full detailed instructions and ingredient amounts.
- Slice a loaf baguette evenly into four slices, then slice vertically across the tops. Hollow each slice out, pulling out most of the bread inside. Set aside.
- Whisk together red wine vinegar, Worcestershire, mustard, garlic and olive oil in a medium bowl.
- Place mushrooms and red onion slices in a large baking dish and pour the marinade over. Stir or toss to coat. Season with salt and pepper.
- Transfer mushroom mixture (along with the marinade) to a large skillet over medium high heat. Cook for five to six minutes, or until mushrooms are tender.
- Transfer mushrooms and onions (with their marinade) back into the baking dish. Add spinach and stir well to combine, coating the spinach as evenly as possible. The spinach will wilt while your baguette is heating.
- Bake baguette slices on a baking sheet in a preheated oven for five minutes, or until warmed through. Carefully stuff each baguette piece with mushroom mixture and top with mozzarella.
More Delicious Mushroom Inspiration
Portobello Mushroom and Spinach Subs
- 1 loaf baguette about 7 ounces
- ¼ cup red wine vinegar
- 1 tablespoon Worcestershire sauce
- 2 tablespoons spicy mustard
- 1 tablespoon minced fresh garlic
- ½ cup extra virgin olive oil
- 2 (6 ounce) packages portobello mushrooms wiped clean and debris removed with a damp towel, then cut into about 2 inch pieces
- ½ cup thinly sliced red onion
- ¼ teaspoon salt more or less, to taste
- ¼ teaspoon black pepper more or less, to taste
- 1 (5 ounce) package baby spinach roughly chopped
- ½ cup shredded mozzarella cheese more or less, to taste
- Preheat your oven to 350 degrees F. Slice baguette evenly into 4 slices. Slice vertically across each top and hollow each slice out, pulling out the bread inside. Set aside.
- In a medium bowl, whisk red wine vinegar, Worcestershire sauce, mustard, garlic and olive oil.
- Place mushrooms and red onion slices in a large baking dish and pour marinade over. Stir and/or toss to coat mushrooms and red onions evenly. Season with salt and pepper and set aside.
- Transfer mushrooms and red onions in their marinade to a large skillet over medium-high heat (keep baking dish to transfer mushroom/onion mixture back into). Cook over medium-high heat for 5 to 6 minutes, stirring constantly, or until mushrooms are tender.
- Transfer mushrooms and onions back into marinade dish. Add fresh chopped spinach and stir well to combine and coat spinach as evenly as possible. Spinach will wilt while your baguette is heating.
- Place baguette slices onto a baking sheet and bake for approximately 5 minutes. Remove from oven and carefully stuff each baguette piece with mixture and top with shredded cheese. Serve immediately.
If provided, nutritional info is a courtesy, is not guaranteed and should only be considered as a guideline.
Originally published January 2012. Updated with new text, new images and recipe slightly revised January 2022.
Adapted from Food Network
We made this tonight and it was delicious!
Amy @ The Blond Cook
Thank you! So glad you enjoyed it Kirsti! 🙂
Amy @ The Blond Cook
Thank you so much, Maggie!