Creating Keto Philly Cheesesteak Casserole is simple when you follow these easy steps:

1. Preheat Oven: Preheat your oven to 350°F (175°C).
2. Sauté Vegetables: In a large skillet, heat olive oil over medium heat. Add sliced onions and bell peppers, sautéing until they are soft, about 5 minutes. Add mushrooms and cook for an additional 3-4 minutes.
3. Cook the Beef: Push the vegetables to the side of the skillet and add the sliced beef. Season with garlic powder, onion powder, salt, and pepper. Cook until the beef is browned, about 5-7 minutes.
4. Combine Ingredients: In a large mixing bowl, combine the sautéed beef and vegetables with heavy cream. Stir well to combine.
5. Layer the Casserole: Pour the mixture into a greased 9×13-inch baking dish. Top with shredded provolone cheese, spreading it evenly.
6. Bake: Bake in the preheated oven for 30-35 minutes or until the cheese is bubbly and golden.
7. Garnish: Remove from the oven and let it cool slightly. Garnish with fresh parsley if desired.
8. Serve: Cut into squares and serve warm.

These steps will guide you in creating this incredible casserole effortlessly.