Low Carb Philly Cheesesteak Casserole

Learn how to prepare a flavorful low carb Philly cheesesteak casserole made with juicy beef, sautéed peppers, onions, and plenty of melted cheese. It’s a hearty keto-friendly dinner that delivers classic cheesesteak flavor without the carbs.

This low carb Philly cheesesteak casserole delivers all the bold diner-style flavors you love while keeping carbohydrates low. Packed with tender beef, savory vegetables, and melted cheese, it’s a comforting meal that also fits perfectly into a keto lifestyle.

I remember experimenting with a bread-free version of a Philly cheesesteak at home for the first time. My teenage son was skeptical when he realized there wasn’t any bread involved. But after the first bite, he immediately changed his mind. Since then, this casserole has become a regular dinner in our house. It recreates everything people love about a traditional Philly cheesesteak juicy beef, sweet caramelized onions, colorful peppers, and gooey melted cheese. The creamy base makes it rich and satisfying while keeping carbs minimal. It’s also ideal for meal prep because it reheats wonderfully throughout the week.

Ingredients for Low Carb Philly Cheesesteak Casserole

For the best results, I prefer using thinly sliced sirloin because it cooks quickly and remains tender. If you’re slicing the beef yourself, placing it in the freezer for about 20 minutes makes it much easier to cut into thin pieces.

Ingredients

• 1.5 lbs beef sirloin (thinly sliced)
• 1 large onion (thinly sliced) – yellow onions work well for their natural sweetness
• 2 bell peppers (thinly sliced) – one red and one green gives a classic cheesesteak flavor
• 2 tablespoons olive oil
• 1 teaspoon garlic powder
• 1 teaspoon salt
• 1/2 teaspoon black pepper
• 8 oz cream cheese (softened) – letting it sit at room temperature helps it blend smoothly
• 1 cup mayonnaise – full-fat mayo gives the richest texture
• 1 cup shredded provolone cheese
• 1 cup shredded cheddar cheese – freshly shredded cheese melts better than packaged

Step-by-Step Instructions

It’s helpful to prepare and measure all ingredients before you begin cooking. Once you start, this recipe comes together quickly, and having everything ready makes the process much easier.

Step 1

Preheat the oven to 375°F. Heat olive oil in a large skillet over medium-high heat. Add the sliced beef in batches so the pan doesn’t get overcrowded. Cook each batch for about 2–3 minutes per side until browned and slightly crisp around the edges. Once cooked, remove the beef from the skillet and set aside.

Step 2

Using the same skillet with the remaining drippings, add the sliced onions and bell peppers. Cook for 5–7 minutes, stirring occasionally, until the vegetables soften and the onions become translucent with lightly caramelized edges. Allowing them to cook slowly helps develop deeper flavor.

Step 3

Return the cooked beef to the skillet with the vegetables. Sprinkle in the garlic powder, salt, and black pepper. Stir everything together well and cook for another minute so the flavors blend evenly.

Step 4

In a mixing bowl, combine the softened cream cheese and mayonnaise. Whisk until the mixture becomes smooth and creamy with no lumps. Spread half of this mixture evenly across the bottom of a 9×13 inch baking dish.

Step 5

Add the beef and vegetable mixture on top of the cream cheese layer, spreading it out evenly. Spoon the remaining cream cheese mixture over the top and spread gently. Finish by sprinkling the provolone and cheddar cheese evenly across the casserole.

Step 6

Place the dish in the oven and bake for 20–25 minutes until the cheese is melted, bubbly, and lightly golden. Let the casserole rest for about 5 minutes before serving so the layers settle and slice neatly.

What to Serve with Low Carb Philly Cheesesteak Casserole

This rich and cheesy casserole pairs well with lighter side dishes that add freshness while keeping the meal low in carbohydrates.

Cauliflower Mash
Creamy cauliflower mash offers the comfort of mashed potatoes while remaining keto-friendly. It also adds fiber and balances the richness of the casserole.

Fresh Green Salad
A crisp salad made with romaine or mixed greens and a light vinaigrette adds refreshing crunch and bright flavor alongside the cheesy dish.

Roasted Asparagus
Roasted asparagus with garlic and lemon brings a slightly smoky flavor that contrasts nicely with the hearty casserole.

Zucchini Noodles
Lightly sautéed zucchini noodles provide extra vegetables and work well for soaking up any flavorful juices from the casserole.

Coleslaw with Apple Cider Vinegar Dressing
Tangy coleslaw adds texture and acidity, helping balance the richness of the beef and cheese while keeping the meal refreshing.

Storage & Serving Tips

Store any leftovers in an airtight container in the refrigerator for up to four days. In fact, the flavors often taste even better the next day, which makes this casserole excellent for meal prep.

To reheat, warm portions in the oven at 350°F for about 15 minutes to keep the cheese soft and melty. If you need a quicker option, you can microwave it, but covering the dish with a damp paper towel helps prevent the cheese from drying out.

This casserole can also be frozen for up to three months. Allow it to cool completely, then wrap tightly in plastic wrap followed by foil. When ready to eat, thaw it overnight in the refrigerator before reheating.

Conclusion

This low carb Philly cheesesteak casserole shows that you can still enjoy classic comfort food while following a low-carb lifestyle. With tender beef, flavorful vegetables, and plenty of melted cheese, it’s satisfying and easy to prepare. The recipe requires minimal effort yet delivers big flavor, making it perfect for busy weeknights or meal prep. Once you try it, your family may not even notice that it’s low carb they’ll just know it tastes amazing.