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A delicious, close-up featured image showcasing a freshly baked Beefy Philly Cheesesteak Casserole with melted cheese and tender beef.

BEST Beefy Philly Cheesesteak Casserole

This Beefy Philly Cheesesteak Casserole recipe transforms the classic sandwich into a shareable, flavor-packed baked dish. Featuring thinly sliced steak, sautéed vegetables, provolone cheese, and a creamy sauce, all layered between toasted Italian bread, this casserole is a comforting and satisfying meal.
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Prep Time 25 minutes
Cook Time 35 minutes
Total Time 1 hour
Servings: 6
Course: Main Course
Cuisine: American
Calories: 650
Ingredients Equipment Method Notes

Ingredients
  

  • 1.5 lbs thinly sliced sirloin steak or shaved steak
  • 1 large onion, thinly sliced
  • 2 bell peppers 1 green, 1 red
  • 8 oz sliced mushrooms
  • 1 tbsp olive oil
  • 1 tsp garlic powder
  • 1 tsp onion powder
  • 1/2 tsp smoked paprika
  • Salt to taste
  • Pepper to taste
  • 1 loaf Italian bread, sliced into 1-inch thick pieces
  • 8 oz provolone cheese, sliced or a blend of provolone and mozzarella
  • 1/2 cup mayonnaise
  • 1/4 cup milk
  • 2 tbsp Worcestershire sauce
  • Optional: Giardiniera for topping
  • Optional: Banana peppers for topping

Equipment

  • 9x13-inch baking dish
  • large skillet
  • baking sheet
  • Large bowl
  • whisk
  • aluminum foil
  • Oven
  • measuring cups and spoons
  • cutting board
  • knife

Method
 

  1. Preheat oven to 350°F (175°C).
  2. Arrange bread slices on a baking sheet and bake for 8-10 minutes, or until lightly toasted. This will prevent sogginess.
  3. Heat olive oil in a large skillet over medium-high heat.
  4. Add onions and bell peppers and cook until softened, about 5-7 minutes.
  5. Add mushrooms and cook for another 3-5 minutes, until they release their moisture and start to brown. Season with salt and pepper. Remove vegetables from skillet and set aside.
  6. In the same skillet, add the thinly sliced steak. Season with garlic powder, onion powder, smoked paprika, salt, and pepper.
  7. Cook until browned and cooked through, about 3-5 minutes. Be careful not to overcrowd the pan; cook in batches if necessary.
  8. In a large bowl, whisk together mayonnaise, milk, and Worcestershire sauce.
  9. In a greased 9x13 inch baking dish, arrange half of the toasted bread slices in a single layer.
  10. Top with half of the steak, half of the sautéed vegetables, and half of the provolone cheese slices.
  11. Repeat layers with the remaining ingredients.
  12. Pour the mayonnaise mixture evenly over the casserole.
  13. Cover the casserole with aluminum foil and bake for 20 minutes.
  14. Remove the foil and bake for another 10-15 minutes, or until the cheese is melted and bubbly and the casserole is heated through.
  15. Let the casserole rest for 5-10 minutes before slicing and serving.
  16. Top with giardiniera or banana peppers, if desired.

Notes

For best results, use freshly sliced provolone cheese. Toasting the bread is crucial to prevent sogginess. The casserole can be assembled ahead of time and refrigerated for up to 24 hours before baking. Adjust the amount of salt and pepper to your liking. Leftovers can be stored in the refrigerator for up to 3 days.