Ground Beef Philly Casserole.

Step 4: Season the Filling

Add the Worcestershire sauce, Italian seasoning, smoked paprika, salt, and black pepper.

Stir everything together thoroughly so the seasoning coats the beef and vegetables.

The Worcestershire sauce is especially useful here because it adds a savory depth that works beautifully with the beef and cheese.

Step 5: Make the Creamy Sauce

In a bowl, combine the softened cream cheese, sour cream, beef broth, Worcestershire sauce, and Dijon mustard.

Whisk until the mixture is as smooth as possible.

It is perfectly fine if the cream cheese leaves a few small lumps at first; they will melt into the hot beef mixture.

Step 6: Combine Everything

Reduce the skillet heat to low.

Pour the creamy sauce over the cooked beef and vegetables. Stir gently until everything is evenly coated.

Allow the mixture to warm for 2–3 minutes. Avoid boiling it aggressively, as excessive heat can cause the creamy sauce to separate.

At this stage, the filling should be rich, creamy, savory, and packed with the flavors of beef, onions, and peppers.

Step 7: Add the Cheese

Spread the beef mixture into an even layer in the skillet.

Sprinkle the provolone, mozzarella, and cheddar evenly over the top.

Provolone gives the casserole that classic cheesesteak-inspired flavor, mozzarella helps create a stretchy melted layer, and cheddar contributes extra sharpness.

Step 8: Bake

Preheat your oven to 375°F (190°C).

Place the skillet in the oven and bake for approximately 15–20 minutes, or until the cheese is completely melted and bubbling around the edges.

For a more golden top, switch the oven to broil for the final 1–2 minutes. Watch it carefully because the cheese can brown quickly.

Step 9: Let It Rest

Remove the casserole from the oven and let it rest for about 5–10 minutes before serving.

This short resting period allows the creamy filling to settle slightly and makes the casserole easier to scoop.

Serving Suggestions

Ground Beef Philly Casserole is filling enough to serve on its own, but it pairs nicely with lighter sides.

Try serving it with:

• A crisp green salad
• Roasted broccoli
• Steamed green beans
• Garlic bread
• Roasted potatoes
• Simple coleslaw

For an extra cheesesteak-inspired experience, you can also serve the casserole alongside toasted hoagie rolls and use the creamy beef mixture as a hearty filling.

Helpful Tips for the Best Results

Use freshly sliced vegetables. Thinly sliced onions and peppers cook more evenly and blend better with the ground beef.

Don’t overcook the beef. Brown it until just cooked through. It will continue cooking in the oven.

Soften the cream cheese first. Room-temperature cream cheese incorporates much more smoothly into the sauce.

Don’t skip the resting time. Giving the casserole a few minutes to cool helps the filling thicken slightly.

Adjust the cheese to your preference. If you love a stronger cheesesteak flavor, increase the provolone. For a milder casserole, use more mozzarella.

Watch the broiler. If you choose to brown the cheese, stay nearby. The topping can go from golden to burnt very quickly.

Make-Ahead Instructions

This casserole can be prepared ahead of time, which makes it convenient for busy evenings.

Prepare the beef and vegetable mixture and combine it with the creamy sauce. Transfer everything to a baking dish, then cover and refrigerate.

When you’re ready to bake, add the cheese topping and bake until the casserole is heated through and the cheese is melted and bubbling. If baking directly from the refrigerator, allow additional baking time.

Storage and Reheating

Store leftovers in an airtight container in the refrigerator for up to 3–4 days.

To reheat individual portions, microwave them until hot, stopping occasionally to stir if needed.

For larger portions, reheat the casserole in a covered oven-safe dish at 350°F (175°C) until warmed through.

Final Thoughts

This Ground Beef Philly Casserole takes everything people love about a cheesesteak—savory beef, sweet onions, colorful peppers, and plenty of melted cheese—and transforms it into a comforting baked dinner.

It’s hearty without being complicated, uses everyday ingredients, and is flexible enough to adapt to what you already have in the refrigerator. Whether you’re feeding the family on a busy weeknight or looking for a cozy meal to prepare ahead, this casserole delivers plenty of rich, cheesy flavor in every bite.