Low Carb Philly Cheesesteak Casserole

The smell of peppers and onions hitting a hot skillet takes me back to late nights when my roommate would experiment with whatever we had in the fridge. We stumbled upon this casserole version during a week when we were both watching our carbs but craving something hearty and satisfying. Now it's become one of those recipes I turn to when I want comfort food without the heaviness of bread.

I made this for my family last Sunday when everyone was crowded around the kitchen counter waiting for football to start. My brother who claims he hates casseroles went back for thirds, and my mom kept asking what the secret ingredient was. The way the provolone gets all bubbly and golden on top makes the whole house smell like a really good sandwich shop.

Ingredients

• 1 ½ lbs thinly sliced beef sirloin or ribeye: Ask your butcher to slice it paper thin against the grain, it makes such a difference in texture
• 2 tablespoons olive oil: Use one tablespoon for searing the beef and another for the vegetables
• 1 large green bell pepper, sliced: Fresh green peppers add that classic crunch and slight bitterness
• 1 large red bell pepper, sliced: Red peppers bring natural sweetness that balances the savory beef
• 1 medium yellow onion, sliced: Yellow onions caramelize beautifully and give depth
• 2 cloves garlic, minced: Fresh garlic is non negotiable here for that aromatic base
• 1 cup sliced mushrooms: They soak up all those beef juices and become little flavor bombs
• 4 oz cream cheese, softened: This creates the creamy sauce that makes it casserole worthy instead of just meat and veggies
• 1 cup shredded provolone cheese: Provolone melts beautifully and has that mild sharpness
• 1 cup shredded mozzarella cheese: Mozzarella gives you those incredible cheese pulls
• 1 teaspoon salt: Enhances all the natural flavors
• ½ teaspoon black pepper: Freshly cracked makes a noticeable difference
• ½ teaspoon smoked paprika: This tiny addition gives such a lovely smoky depth

Instructions

Preheat your oven to 375°F and get your ingredients ready:

Having everything prepped before you start cooking makes this come together so much smoother.

Sear the beef:

Heat 1 tablespoon olive oil in a large skillet over medium-high heat, add the beef slices with salt, pepper, and smoked paprika, and cook until browned, about 3-4 minutes, then remove and set aside.

Cook the vegetables:

Add the remaining olive oil to the skillet and sauté the onions, bell peppers, and mushrooms until softened, about 6-8 minutes, then stir in garlic for 1 more minute.

Create the creamy base:

Reduce heat to low, add the cream cheese to the vegetables, and stir until melted and completely combined.

Combine everything:

Return the cooked beef to the skillet and mix well with the creamy vegetable mixture until evenly distributed.

Assemble the casserole:

Transfer the mixture to a greased 9x13-inch casserole dish and sprinkle the provolone and mozzarella evenly over the top.

Bake until bubbly:

Bake for 15-18 minutes until the cheese is melted, bubbly, and lightly golden on top.

Let it rest:

Let the casserole sit for 5 minutes before serving, this helps everything set so you get nice clean servings.

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This recipe has saved me so many times when friends announce they are doing keto or low carb. Last month my neighbor texted me at 6 PM saying she needed something for a dinner party and I walked over with a dish of this. She said it was the first time in months her husband actually went for seconds without complaining about missing pasta.

Making Ahead

You can assemble the entire casserole up to 24 hours in advance and keep it covered in the refrigerator. The flavors actually develop more when given time to meld together. Just add an extra 5-10 minutes to the baking time if cooking straight from the fridge.

Freezing Instructions

This casserole freezes beautifully for up to 3 months. I like to make two at once and freeze one for those nights when cooking feels impossible. Thaw overnight in the refrigerator before baking, or bake from frozen at 350°F for about 45-50 minutes until heated through.

Serving Ideas

Serve with a crisp green salad dressed with vinaigrette to cut through all that rich cheese, or pair with roasted cauliflower for an extra low carb veggie boost.

• A drizzle of hot sauce adds a nice kick for spice lovers
• Fresh chopped parsley brings color and brightness
• Sliced jalapeños on top make it feel extra special

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There is something so satisfying about taking a classic sandwich and transforming it into a casserole that feeds a crowd. Hope this becomes a regular in your rotation too.

Recipe FAQs

→ Can I make this ahead of time?

Yes, you can assemble the entire casserole up to 24 hours in advance and store it covered in the refrigerator. When ready to bake, add about 5-10 minutes to the cooking time if baking cold from the refrigerator.

→ What cut of beef works best?

Thinly sliced ribeye or sirloin are traditional choices that offer great flavor and tenderness. You can ask your butcher to slice the beef thinly, or partially freeze it for easier slicing at home.

→ Can I freeze leftovers?

This casserole freezes exceptionally well. Portion leftovers into airtight containers and freeze for up to 3 months. Thaw overnight in the refrigerator and reheat in the oven or microwave until heated through.

→ How do I make it even lower in carbs?

Reduce the bell peppers and onions slightly, and increase the mushrooms. You can also use a blend of provolone and sharp cheddar which allows you to use less cheese while maintaining flavor.

→ What sides pair well with this?

A crisp green salad with vinaigrette, steamed broccoli, cauliflower rice, or roasted vegetables make excellent accompaniments. The dish is filling enough to stand alone as well.