Low Carb Philly Cheesesteak Casserole

The first time I made this casserole, my husband looked at me skeptically when I said it was a low-carb version of his favorite sandwich. One bite later and he was already asking when we could have it again. That's the magic of this dish, it captures everything you love about a Philly cheesesteak without the bread overload.

Last winter, when my sister was visiting and trying to cut back on carbs, I served this for dinner. She literally paused mid-bite and asked if I was sure this was actually diet-friendly. The way the provolone gets all golden and bubbly on top makes it feel indulgent, not deprived.

Ingredients

• Thinly sliced beef sirloin or ribeye: I've learned that asking the butcher to slice it paper-thin makes all the difference in texture
• Olive oil: Two tablespoons might seem like a lot, but you need both for properly cooking the beef then sautéing those vegetables
• Green and red bell peppers: The combination gives you that classic cheesesteak vibe plus beautiful color contrast
• Yellow onion: Slice it thin so it softens properly and melds into the creamy vegetable base
• Garlic: Fresh minced garlic is non-negotiable here, it adds that aromatic depth you can't get from powder
• Sliced mushrooms: They soak up all those savory juices and add a meaty texture without extra carbs
• Cream cheese: This is the secret ingredient that transforms everything into a cohesive, rich casserole
• Shredded provolone and mozzarella: The provolone brings that authentic cheesesteak flavor while mozzarella adds the perfect melt
• Salt, black pepper, and smoked paprika: The smoked paprika is my addition, it gives the beef this beautiful depth

Instructions

Get your oven ready:

Preheat to 375°F and grab your 9x13 dish, giving it a quick spray or rub of oil so nothing sticks later

Cook the beef first:

Heat one tablespoon olive oil in your largest skillet over medium-high, then season and brown the beef slices in batches so they sear rather than steam

Sauté the vegetables:

Add that remaining oil to the same skillet and cook your peppers, onions, and mushrooms until they're soft and fragrant, about 8 minutes

Add the garlic:

Toss in the minced garlic for just one minute, you want it aromatic but not burned

Make it creamy:

Turn the heat down low and stir in the cream cheese until it melts into a gorgeous coating that brings everything together

Combine and transfer:

Fold the beef back into the skillet, then spread the whole mixture into your prepared baking dish

Add the cheese topping:

Sprinkle both cheeses evenly across the top, making sure every corner gets covered

Bake until bubbly:

Let it go for 15 to 18 minutes until you see those gorgeous golden spots and the cheese is perfectly melted

The waiting game:

Let it rest for 5 minutes before serving, this helps everything set and makes serving so much easier

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This became my go-to meal when friends come over for casual dinner nights. There's something about pulling a bubbling, cheese-topped casserole out of the oven that makes everyone feel immediately at home and well-fed.

Making It Your Own

I've started adding sliced jalapeños to half the dish for anyone who wants some heat. The way the peppers mellow slightly while baking is just perfect, still spicy but not overwhelming.

Protein Swaps

When my sister visits, she prefers chicken, so I'll slice boneless breasts thin and cook them the same way. It's lighter but still satisfies that cheesesteak craving, and the cream cheese sauce works beautifully with poultry.

Perfect Pairings

A crisp green salad with a simple vinaigrette cuts through all that rich cheese and cream. Sometimes I'll serve roasted broccoli on the side, its slight bitterness balances everything so nicely.

• Make extra for tomorrow's lunch, the flavors deepen overnight
• Keep some fresh parsley handy for a pop of color on top
• Leftovers reheat covered at 350°F for about 15 minutes

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Every time I make this, I'm reminded that eating low-carb doesn't mean sacrificing comfort. This casserole proves you can have all the satisfaction of a cheesesteak and still wake up feeling great the next morning.

Recipe Q&A

→ What cut of beef works best?

Thinly sliced beef sirloin or ribeye works best. You can ask your butcher to slice it thin or partially freeze the beef and slice it yourself for easier cutting.

→ Can I make this ahead of time?

Yes, assemble the casserole up to 24 hours in advance and refrigerate. Add 5-10 minutes to the baking time if baking cold from the refrigerator.

→ Is this truly low-carb?

With only 7 grams of carbohydrates per serving, this dish fits well into low-carb and keto lifestyles. The cheese and beef provide plenty of protein and fat to keep you satisfied.

→ What vegetables can I add?

Beyond the bell peppers and onions, you can add sliced mushrooms, spinach, or even diced jalapeños for extra heat. Just keep in mind that additional vegetables may slightly affect the carb count.

→ How do I store leftovers?

Store cooled leftovers in an airtight container in the refrigerator for up to 4 days. Reheat in the microwave or oven at 350°F until heated through.

→ Can I freeze this casserole?

Yes, freeze before baking by wrapping the dish tightly in plastic and foil. Thaw overnight in the refrigerator before baking as directed, or bake frozen at 350°F for about 45 minutes.