Portobello Cheesesteak Sandwiches
Meaty portobello cheesesteak sandwiches! Hearty, filling hoagies filled with portobello mushrooms, caramelized onions, and peppers.
This portobello cheesesteak sandwich is a hearty, meaty sandwich and the perfect vegetarian option for my friends who crave old, delicious meals like I do.
These portobello mushroom sandwiches are perfect for weeknight dinners—a big sandwich covered in caramelized onions, peppers, mushrooms, and melty provolone cheese.
Serve with roasted potatoes for a lighter take on traditional cheesesteak and fries. See below for more details, or head to the full recipe below.
Why I love this recipe
As an East Coast girl, I’ve had my fill of Philly-style cheesesteak sandwiches in my life. It was one of my favorite meals as a kid, and now as a long-time vegetarian, I’ve traded the steak for portobellos while keeping the juicy peppers, onions, and melty cheese.
Dairy-free? I bet that my cheddar cheese sauce would be amazing drizzled on this; or a few dollops of my vegan mozzerella cheese.
Ingredient Notes
- Portobello: Big, meaty portobello mushrooms are best for this sandwich, but sliced button mushrooms can be used as an alternative if needed.
- Peppers: I don’t think the colors matter for this sandwich; I just like doing a red and green for color contrast.
- Onions: The caramelized onions are key to this sandwich, adding a significant amount of flavor and texture to these portobello cheesesteaks. I recommend taking the time to really caramelize them and not rushing them.
- Hoagie Rolls: Head to the deli to grab good hoagie rolls for these sandwiches. They deserve sturdy, crusty bread that can hold the filling.
- Provolone Cheese: I grab sliced cheese from the deli counter whenever I am making these sandwiches. Since we aren’t big provolone cheese eaters (besides these sandwiches, obviously), I didn’t want an entire package of sliced cheese going to waste in the fridge. I do this trick often when I want a few slices, and it usually ends up being only a dollar or two, with no waste!
How to Make
Step 1: Caramelize the Mushrooms
While these portobello cheesesteak sandwiches are pretty effortless, you do need to allow enough time for the onions to become really dark and caramelized. This can take 20-30 minutes, a relatively quick process, so slice the onions, add them to the pan, and do something else. Stir them every 5 minutes or so, but this is a great time to catch up on laundry, prep other meals for the week, hang with your family, or feed a baby!
Make sure to add a pinch of salt here to help the onions release their juices.
Step 2: Add the Mushrooms
Remove the stems and gills from the portobello mushrooms and slice, then add to the pan. Cook the mushrooms and let them soften a bit, then cook, stirring often, until they are browned and cooked down.
Step 3: Fill the Hoagie and Bake
Add the peppers and cook until tender. While the peppers are cooking, split the hoagies and place in a preheated oven and cook for 2-3 minutes until toasted. This helps prevent the hoagie bread from becoming overly soggy with the filling.
Remove the toasted bread, then fill with the mushroom, onion and pepper filling. Top with a slice or two of provolone cheese and pop into the oven and toast until the cheese is melty.
How to Serve
I like serving these with a green salad for texture contrast, but they are also fantastic with my herb roasted potatoes. Hoagie rolls are a must for me, but you can also serve them in a bun of your choice, or in a wrap.
I’m also a big fan of spice, so I like topping my canned hot peppers in oil (for a very Italian twist) or chili crisp.
Tips for Success
- Choose the Right Portobellos: I like to choose large, firm caps with gills that aren’t wet or mushy. I prefer to scrape out the gills for a less “earthy” flavor, but that’s optional.
- Sear Mushrooms: Slice the mushrooms into 1/2-inch strips so they cook properly. If you slice them too thin, they’ll shrivel when cooked.
- Use a large enough pan: I use my large cast-iron pan for making these sandwiches, giving the mushrooms, onions, and peppers enough space to sear properly without steaming.
- Choose Good Bread: For these sandwiches, I grab rolls from the bakery section of our grocery store. They tend to be a bit heartier than ones you’ll find in the bread aisle.
- Don’t skip the broil! Put the stuffed sandwiches under the broiler and let them melt to perfection. Then, remove and enjoy… with plenty of napkins.
More Mushroom Recipes
- Creamy Mushroom Pasta
- Best Vegan Mushroom Gravy
- Mushroom Fajitas with Cashew Queso
- Mushroom Wellington
- Vegetarian Mushroom Stroganoff
- Mushroom Galette
If you try this portobello cheesesteak sandwich recipe, let me know! Leave a comment, rate it, and tag your Instagram photos with #delishknowledge . I absolutely love seeing your creations. Happy cooking!
Portobello Cheesesteak Sandwiches
Ingredients
- 1 tablespoon olive oil
- 3 large white onions, thinly sliced
- 4 bell peppers, thinly sliced into strips (I used 1 red and 1 green pepper)
- 3/4 teaspoon salt
- 4 garlic cloves, minced
- 1 1/2 teaspoon dried oregano
- 1/4 teaspoon crushed red pepper
- 8 portobello mushroom caps, gills removed and sliced
- 8 slices provolone cheese
- 4 large hoagie rolls
Instructions
- Heat the olive oil in a large skillet over medium heat. Add the onions and saute until very caramelized, about 25-30 minutes, stirring occasionally. May take longer depending on the size of your onion slices.Â
- Add in the bell peppers and cook until just tender, then add in the salt, garlic, oregano, crushed red pepper and mushrooms.Â
- Cook until mushrooms are browned, about another 10-15 minutes.Â
- Preheat the oven to 400 degrees F. and place the split hoagie rolls on a baking sheet. Place the rolls in the oven until toasted. Divide the mushroom mixture among the rolls and top each with a slice of provolone cheese.Â
- Place the sandwiches back in the oven until cheese is melted. Remove from the oven and serve immediately.Â
These look so good! I lived in Philly for years and never got cheesesteaks (was plant based back then, too) but these look so much better anyway!
Yes, let me know what you think! You can use any cheese you’d like for these too. They are so meaty and yummy!
My kids wouldn’t eat this because onions, peppers, and mushrooms, but what do they know. Husband and I thought it was delicious. He’s lasted three more days (longer than two) than I expected with my current meatless cooking – mostly thanks to your recipes!