Ingredients
For the filling:
1 ½ lbs thinly sliced beef steak (ribeye or sirloin work great)
2 tablespoons olive oil or butter
1 medium onion, thinly sliced
1 large green bell pepper, thinly sliced
1 large red bell pepper, thinly sliced (optional, adds slight sweetness)
8 oz mushrooms, sliced
2 cloves garlic, minced
Salt and pepper, to taste
For the creamy cheese mixture:
4 oz cream cheese, softened
½ cup sour cream
½ cup mayonnaise
1 teaspoon Worcestershire sauce
1 teaspoon onion powder
1 teaspoon garlic powder
For topping:
1 ½ cups shredded provolone or mozzarella cheese
½ cup shredded cheddar cheese (optional for extra sharpness)
Instructions
Preheat the oven to 375°F (190°C).
Sauté the beef:
In a large skillet over medium-high heat, add 1 tablespoon of olive oil or butter.
Sear the sliced steak until browned and cooked through (about 5–7 minutes). Season with salt and pepper.
Remove from skillet and set aside.
Cook the vegetables:
In the same skillet, add remaining oil/butter.
Add onions, peppers, mushrooms, and garlic. Cook until softened and slightly caramelized, about 8–10 minutes.
Add the cooked beef back to the skillet and combine. Turn off heat.
Make the creamy mixture:
In a mixing bowl, combine cream cheese, sour cream, mayo, Worcestershire sauce, onion powder, and garlic powder. Mix until smooth.
Assemble the casserole:
In a 9×13-inch casserole dish, spread the beef and vegetable mixture evenly.
Pour the creamy mixture over the top and mix lightly to combine.
Sprinkle the shredded cheeses evenly over the top.
Bake:
Bake uncovered for 20–25 minutes, or until the cheese is melted, bubbly, and golden brown.
Optional broil:
For a golden cheese top, broil for an additional 2–3 minutes. Watch closely!
Serve:
Let it cool for a few minutes before serving. Great with a side salad or roasted low-carb veggies.
Storage Tips
Fridge: Keeps well for up to 4 days in an airtight container.
Freezer: Freeze before baking, or after baking once cooled. Reheat at 350°F until warmed through.