Low Carb Philly Cheesesteak Casserole

Last winter, my sister mentioned she was doing low-carb and really missing her favorite comfort foods. I experimented in the kitchen one snowy afternoon, throwing together the classic Philly cheesesteak flavors she loved but reshaping them into a bake-and-forget casserole.

That first test run, my family ended up hovering around the oven watching the cheese bubble up golden brown. Even my carb-loving husband went back for seconds and asked when I was making it again.

Ingredients

• 1 ½ lbs thinly sliced beef sirloin or ribeye: Ask your butcher to slice it paper-thin, or freeze for 20 minutes and slice it yourself at home for that authentic cheesesteak texture
• 2 tablespoons olive oil: Divided use helps cook the beef and vegetables separately so each ingredient gets proper attention
• 1 large green bell pepper and 1 large red bell pepper: The colorful mix brings sweetness and those classic Philly flavors
• 1 medium yellow onion: Slice them into thin strips, they cook down sweet and tender in the creamy base
• 2 cloves garlic, minced: Add this at the very end so it does not burn and become bitter
• 1 cup sliced mushrooms: They shrink quite a bit while cooking, so do not be afraid to pile them in
• 4 oz cream cheese, softened: This creates the velvety sauce that binds everything together
• 1 cup shredded provolone cheese: That authentic cheesesteak flavor comes through loud and clear
• 1 cup shredded mozzarella cheese: Provides the gorgeous golden brown melt on top
• 1 teaspoon salt, ½ teaspoon black pepper, and ½ teaspoon smoked paprika: The paprika adds a subtle smoky depth that really makes this taste like it came from a sandwich shop

Instructions

Get the oven ready:

Preheat to 375°F and grab a 9x13-inch casserole dish

Cook the beef first:

Heat half the olive oil in a large skillet over medium-high heat, season the beef with half the salt, pepper, and paprika, then brown quickly for 3-4 minutes

Sauté the vegetables:

Add the remaining oil to the same skillet and cook the peppers, onions, and mushrooms until softened, about 6-8 minutes

Add the garlic:

Stir in the minced garlic for just one minute so it releases fragrance without burning

Make it creamy:

Reduce heat to low and stir in the cream cheese until melted and everything is coated

Combine and transfer:

Return the beef to the skillet, mix well, then spread the mixture into your prepared baking dish

Bake until bubbly:

Sprinkle both cheeses evenly over the top and bake for 15-18 minutes until golden

Let it rest:

Wait 5 minutes before serving so the cheese sets slightly and portions hold together beautifully

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This became my go-to when friends come over for casual weeknight dinners. Everyone assumes it took hours to make, and I never correct them.

Make It Your Own

Sometimes I swap in sliced chicken or turkey when beef feels too heavy, and the result is still incredibly satisfying. You can also add sliced jalapeños on top before baking if your family loves some heat.

Serving Suggestions

A crisp green salad with a simple vinaigrette balances the richness perfectly. The contrast of cool, fresh greens against the warm, cheesy casserole makes the whole meal feel complete.

Storage and Reheating

This keeps beautifully in the refrigerator for up to four days and actually develops more flavor overnight. Reheat individual portions in the microwave for about two minutes, covered loosely with a paper towel.

• Freeze portions in airtight containers for up to three months
• Thaw overnight in the refrigerator before reheating
• Add a sprinkle of fresh cheese when reheating to revive the melt

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Hope this becomes a regular in your rotation like it has in mine.

Recipe Q&A

→ Can I make this ahead of time?

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

→ What other proteins work well?

Chicken breast strips or ground turkey make excellent lighter options. Adjust cooking time accordingly as these lean proteins cook faster than beef.

→ How do I store leftovers?

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

→ Can I freeze this casserole?

Yes, freeze before baking for up to 3 months. Thaw overnight in the refrigerator, then bake as directed, adding 10-15 minutes if needed.

→ What vegetables can I substitute?

Try zucchini, spinach, or broccoli in place of mushrooms. For lower carbohydrates, reduce the peppers and increase the mushrooms or spinach.

→ Is this suitable for keto diets?

With only 7 grams of carbohydrates per serving, this fits well into ketogenic meal plans when paired with other low-carb sides.