High-Protein Cheesesteak Casserole
High-Protein Cheesesteak Casserole
Skillet cheesesteak casserole with tender beef, peppers, mushrooms, and melted cheese — low-carb, sugar-free, and ready in 35 minutes
This high-protein cheesesteak casserole brings all the classic Philly flavors into one easy skillet. Thinly sliced beef is cooked with peppers, onions, and mushrooms, then topped with plenty of melted cheese. Every serving delivers 35 g of protein and only 5 g net carbs.
Low-carb, sugar-free, and perfect for a hearty weeknight dinner.
Why you’ll love this casserole
- 35g protein per serving — a complete high-protein meal
- Only 5g net carbs and fully sugar-free
- All the classic cheesesteak flavors in one skillet
- Ready in about 35 minutes
- Cheesy, savory, and satisfying
- Great for meal prep or family dinners
Health notes
- High protein: Beef and cheese deliver the protein.
- Low carb: No bread — peppers and mushrooms keep net carbs low.
- Sugar-free: No added sugar in the seasoning or sauce.
- One-skillet: Minimal cleanup.
Key element — slice the beef thin
Thinly sliced steak cooks quickly and stays tender. Partially freeze the meat for 20–30 minutes to make slicing easier.
Ingredients
Casserole
- 1½ lb (680g) thinly sliced steak (ribeye, sirloin, or top round)
- 1 Tbsp olive oil or avocado oil
- 1 medium onion, sliced
- 1 green bell pepper, sliced
- 1 red or yellow bell pepper, sliced
- 8 oz (225g) mushrooms, sliced
- 2 garlic cloves, minced
- 1 tsp Worcestershire sauce (sugar-free if possible)
- ½ tsp salt
- ¼ tsp black pepper
- ½ tsp garlic powder
- ½ tsp onion powder
Cheese topping
- 1½ cups shredded provolone or mozzarella
- ½ cup shredded cheddar (optional)
- Optional: chopped parsley for garnish
Swaps
- Ground beef: Use ground beef if you prefer a quicker option.
- Chicken: Swap the steak for thinly sliced chicken breast.
- Extra creamy: Stir in 2 oz cream cheese before adding the shredded cheese.
- Spicy: Add sliced jalapeños or a pinch of red pepper flakes.
Instructions
| 1 | Prep the beef. If needed, partially freeze the steak for 20–30 minutes, then slice it very thinly against the grain. Season with salt, pepper, garlic powder, and onion powder. |
| 2 | Cook the vegetables. Heat the oil in a large oven-safe skillet over medium-high heat. Add the onion, peppers, and mushrooms. Cook 6–8 minutes until softened and lightly browned. Stir in the garlic for 30 seconds, then transfer the vegetables to a plate. |
| 3 | Cook the steak. In the same skillet, add the sliced steak in a single layer (work in batches if needed). Sear 1–2 minutes per side until just cooked. Return the vegetables to the pan, add the Worcestershire sauce, and toss everything together. |
| 4 | Add the cheese and melt. Sprinkle the shredded provolone (and cheddar if using) evenly over the top. Place the skillet under the broiler for 2–4 minutes until the cheese is melted and bubbly. Garnish with parsley and serve. |
Pro tips
- Thin slices of steak cook fast and stay tender — don’t overcook them.
- A hot skillet gives the best sear and flavor.
- If your skillet isn’t oven-safe, transfer everything to a baking dish before adding the cheese.
- This reheats well — keep leftovers covered in the refrigerator.
- For extra richness, stir a spoonful of cream cheese into the pan before topping with shredded cheese.
Nutrition
| Nutrient | Per serving |
|---|---|
| Calories | 420 |
| Protein | 35g |
| Net carbohydrates | 5g |
| Total carbohydrates | 7g |
| Fiber | 2g |
| Total fat | 26g |
| Sodium | 580mg |
Estimates based on steak, peppers, mushrooms, and provolone. Exact numbers vary with cut of beef and cheese brands.
Variations
Classic Philly style
Use provolone only and keep the peppers and onions classic.
Mushroom Swiss
Swap the provolone for Swiss and load up on the mushrooms.
Chicken cheesesteak
Use thinly sliced chicken breast instead of steak.
Extra creamy
Stir in cream cheese or a splash of heavy cream before adding the shredded cheese.
Storage
| Method | Time | Notes |
|---|---|---|
| Refrigerator | Up to 4 days | Store covered |
| Freezer | Up to 2 months | Freeze after cooking; thaw and reheat |
| Reheat | Skillet or oven | Oven keeps the cheese melted and golden |
FAQ
Test your knowledge
5 quick questions about this cheesesteak casserole
1. Protein per serving?
2. Net carbs per serving?
3. Why slice the steak thin?
4. About how long does this take?
5. Best way to reheat leftovers?
