Name: Philly Cheesesteak Stuffed Portobello Mushrooms
Prep time: 10 min
Cook time: 20 min
Total time: 30 min
Yield: 6
Cuisine: American
Ingredients: 6 large portobello mushrooms, stem and gills removed; 8 oz. top sirloin steak, if more than an 1″ thick thinly slice in half; salt & pepper to season; 1 green pepper, diced; 1 cup diced sweet onion; 1 red pepper, julienned; 1/4 cup sour cream; 2 tablespoons mayonnaise; 1 tablespoon prepared horseradish; 1/2 teaspoon garlic powder; 1/4 teaspoon ground black pepper; 4 oz. shredded provolone cheese; parsley for garnish

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These easy Philly Cheesesteak Stuffed Mushrooms are packed with seared top sirloin, provolone, peppers, onions and a killer sauce. You won’t miss the bread at all with this low-carb and guilt-free dinner!

If you’re a stuffed mushroom lover like me then you definitely need to make my Mini Portobello Margherita Pizzas or my Quick Crab Stuffed Mushrooms.

stuffed mushroom on a plate with peppers and melted cheese

Table of Contents

Easy Low Carb Stuffed Mushrooms
What You’ll Need
What Are The Best Mushrooms for Stuffed Mushrooms?
How to Make Philly Cheesesteak Stuffed Mushrooms
Tips for Success
What to Serve with Portobello Stuffed Mushrooms
How to Store & Reheat Leftovers
Get the Recipe

Easy Low Carb Stuffed Mushrooms

We all have those moments when we crave a big, crunchy-yet-soft, filling-filled, flavorful sandwich. And most of the time, my go-to sandwich like that is a Philly cheesesteak sandwich.

Yes, sometimes I go out and order that pleasing sandwich, and other times, I just figure out how to make a healthier version at home! And just like that, here comes my Philly Cheesesteak Stuffed Portobello Mushrooms!

They satisfy all my cravings on top of being so simple to make and healthy. These stuffed mushrooms only take about a half hour to make. And my whole family loves them! It’s definitely a fun way to mix up dinner when you’re in a rut.

For these stuffed mushrooms I take a top sirloin and cook it in a skillet to be about medium rare. Then the sliced steak is tossed with peppers, onions, and a creamy horseradish sauce. That incredible filling goes into portobello mushroom caps and is topped with provolone cheese. They’re baked and they come out perfectly cooked and ready to eat!

stuffed mushroom on a sheet tray with peppers, melted cheese, and herbs

What You’ll Need

The ingredient list is pretty simple. You just need to run out to grab a few things at the store and then you’re good to go! Remember, the exact amounts for everything are down below in the recipe card.

Portobello Mushrooms: The larger caps are better for this recipe. Alternatively, you can cut the meat up into small pieces and use smaller mushrooms, too.
Top Sirloin: This is the cut that I like to use for this recipe. But you can use whatever steak you like! You could even use ground beef if that’s all that you have.
Peppers: I used green and red bell peppers but you could also use orange or yellow ones, too.
Onion: Sweet onions work great for this recipe.
Sour Cream: You could also use plain Greek yogurt as a healthier option.
Mayonnaise: Use any type of mayonnaise you like for this part.
Prepared Horseradish: More or less can be used depending on how much you like the spiciness of horseradish.
Garlic Powder: Granulated garlic or garlic salt could also be used.
Black Pepper
Provolone Cheese: This is the type of cheese that’s normally used for a Philly cheesesteak, but you could also use cheddar or swiss.
Parsley: This is for garnish, so if you don’t have any – that’s ok! You could also use another fresh herb like chives or sliced green onions would also be delicious.

What Are The Best Mushrooms for Stuffed Mushrooms?

I really love using portobello mushrooms for this recipe because they are large and can be stuffed with lots of meat and veggie filling. This makes them a great option not for just a snack or appetizer, but they are big enough to serve for dinner.

That doesn’t mean that you can’t use smaller mushrooms though! Baby Bella or button mushrooms can also work, but you’ll have to chop the meat and vegetables into smaller pieces so they fit into the cap.

philly cheesesteak stuffed mushrooms on a sheet tray garnished with fresh herbs

How to Make Philly Cheesesteak Stuffed Mushrooms

Here’s how to make this simple and low-carb recipe.

First, prepare the mushrooms. You’ll need to remove the stems and take out the gills from the mushroom cap. You can do this with the edge of a spoon. Then lay them flat on a sheet tray and spray them lightly with cooking oil. You can also season them with a sprinkle of salt if you’d like.

Next, cook the steak. You can do this in a hot skillet or even on the grill. Always allow the meat to rest before slicing.

Cook the peppers and onion while the meat is resting. You can do this right in the same pan. Cook them until they are soft and a little translucent.

sliced steak and vegetables in a glass bowl

Slice the steak and then add them to a bowl with the filling ingredients. Add the sliced steak, cooked vegetables, mayonnaise, sour cream, garlic powder, horseradish, black pepper, and cheese.

cheese, slice vegetables, and dollops of cream sauce in a glass bowl

sliced steak and vegetables tossed in a cream sauce in a bowl

Create the filling. Coat the steak and vegetables with the creamy sauce.

about to be cooked philly cheesesteak stuffed mushrooms on a sheet tray garnished with fresh herbs

Stuff the portobello caps with the filling. Then bake for about 20 minutes or until the mushrooms are tender. When they are done, you can serve them immediately and garnish them with fresh parsley.

Tips for Success

Here are some tricks and tips I learned while making these Philly Cheesesteak Stuffed Mushrooms.

Don’t overcook the steak. You want the steak to be just about medium rare when you first cook it. If you overcook it in the beginning, it will be tough and not as flavorful.
You can make the filling ahead of time. If you want to save even more time, you can make the filling and keep it in the fridge until you’re ready to bake the mushrooms.
No horseradish? No problem! You can simply omit the horseradish if you don’t have any. Or you can add a little bit of spicy mustard or even a tiny bit of wasabi paste for that added kick!

What to Serve with Portobello Stuffed Mushrooms

These stuffed mushrooms are a great snack or meal option. Here are some of my favorite recipes to serve alongside them!

Make a dipping sauce. You can dip or drizzle your favorite sauce over these mushrooms for added flavor and creaminess. Is it any surprise that I’m going to suggest my Boom Boom Sauce?! You could also mix a little extra of the mayo, sour cream, dijon mustard or horseradish for an easy sauce.
Healthy fries on the side. Keep the theme going of “healthy takeout” and whip up some of my favorite good-for-you french fries. My Air Fryer Sweet Potato Fries and Crispy Zucchini Fries are two great options.
Low-carb side options. Parmesan Roasted Cauliflower, Easy Spaghetti Squash, and/or Simple Garlic Spinach are some of my other favorite low-carb recipes to go with this recipe.

How to Store & Reheat Leftovers

I recommend eating these Philly Cheesesteak Stuffed Mushrooms right away for the best flavor and texture. If you do have leftovers, you can store them in the fridge for 1-2 days. To reheat, I suggest putting them back in the oven for a few minutes. Or you could use the air fryer, too!