Keto Philly Cheesesteak Mushrooms (Printable Version)

Portobello mushrooms filled with savory steak, peppers, and melted cheese for a flavorful low-carb dish.

# What You Need:

→ Mushrooms

01 - 4 large portobello mushroom caps, stems and gills removed
02 - 2 tablespoons olive oil
03 - 1/4 teaspoon salt
04 - 1/4 teaspoon black pepper

→ Filling

05 - 1 pound thinly sliced ribeye steak or sirloin
06 - 1 tablespoon olive oil
07 - 1 small yellow onion, thinly sliced
08 - 1 small green bell pepper, thinly sliced
09 - 1 small red bell pepper, thinly sliced
10 - 2 cloves garlic, minced
11 - 1/2 teaspoon salt
12 - 1/4 teaspoon black pepper
13 - 1/2 teaspoon smoked paprika

→ Topping

14 - 1 cup shredded provolone or mozzarella cheese

# How To Make:

01 - Preheat oven to 400°F. Line a baking sheet with parchment paper.
02 - Brush mushroom caps on both sides with olive oil. Sprinkle with salt and pepper. Place gill-side up on prepared baking sheet and roast for 10 minutes.
03 - While mushrooms roast, heat 1 tablespoon olive oil in a large skillet over medium-high heat. Add onion and bell peppers; sauté for 4 to 5 minutes until softened.
04 - Add minced garlic and cook for 1 minute. Push vegetables to the side of the skillet.
05 - Add sliced steak, season with salt, pepper, and smoked paprika. Cook, stirring, until just browned, about 3 to 4 minutes. Mix steak and vegetables together. Remove from heat.
06 - Remove mushrooms from oven. Drain any accumulated liquid from the caps.
07 - Fill each mushroom cap with the steak and pepper mixture. Top evenly with shredded cheese.
08 - Return to oven and bake for an additional 8 to 10 minutes, until cheese is melted and bubbly.
09 - Serve hot, garnished with fresh parsley if desired.

# Cooking Tips:

01 -
  • It tastes indulgent and cheesy while keeping carbs nearly invisible, so you never feel like you're sacrificing flavor.
  • Portobello mushrooms are naturally meaty enough that the steak filling feels substantial and satisfying without any bread.
  • The whole thing comes together in under 45 minutes, making it perfect for weeknight dinners when you want restaurant-quality results.
02 -
  • Drain every drop of liquid from those mushroom caps after the initial roast, or your masterpiece will become a soggy disappointment. I learned this by making a memorable mistake in front of guests.
  • Don't skip brushing the mushrooms with oil before roasting, because that step is what gives them texture and prevents them from turning into rubber.
  • The steak must be sliced thin and cooked quickly, otherwise it'll toughen up and the whole dish suffers. I now ask my butcher specifically for shaved steak for this reason.
03 -
  • Buy the largest portobello mushrooms you can find because they're easier to fill and less likely to collapse during cooking.
  • If your mushrooms release too much liquid, pat them dry with a paper towel before filling, and save that liquid for beef broth if you're being resourceful.
  • Make the filling ahead of time and refrigerate it, then assemble and bake the mushrooms fresh for maximum texture and cheese pull.
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