Philly Cheesesteak Casserole

Beef • Peppers • Onions • Provolone • A ridiculous amount of cheese

Yield: 8×8 or 9×9 dish (serves 4–6)
Oven: 375°F (190°C)

Ingredients

For the Meat & Veg:

1 ½ lbs (680g) thinly sliced ribeye or sirloin (see note on meat)
1 tbsp olive oil
2 tbsp unsalted butter
1 large yellow onion, halved and thinly sliced
1 large green bell pepper, thinly sliced
8 oz cremini mushrooms, sliced (optional but traditional-adjacent)
3 cloves garlic, minced
1 tsp salt (adjust to taste)
½ tsp black pepper
½ tsp smoked paprika (optional, for depth)

For the Cheese Situation:

8 slices provolone cheese (not the pre-sliced plastic kind; get decent deli provolone)
1 ½ cups shredded provolone or mozzarella (or a mix)
¼ cup grated Parmesan

For the Custard Base:

4 large eggs
½ cup heavy cream
¼ cup beef broth
1 tsp Worcestershire sauce

Optional Crown:

Butter-toasted breadcrumbs or crushed buttery crackers

Method

1. The Meat

Critical: If your beef is not shaved thin, this casserole will be tough. Ribeye is ideal; sirloin works. Place the meat in the freezer for 20–30 minutes before slicing. This firms it up, allowing you to slice it paper-thin.

Slice against the grain into thin strips, then cross-cut into bite-sized pieces.

2. The Vegetables

Heat a large skillet over medium-high. Add the butter and oil. When it foams, add the onions and peppers. Cook undisturbed for 3–4 minutes to get color, then stir. Continue cooking until soft and lightly charred at the edges, about 8–10 minutes.

Add mushrooms if using. Cook until they release their liquid and it evaporates. Add garlic, salt, pepper, and paprika. Stir for 1 minute until fragrant.

Remove vegetables from the skillet and set aside.

3. The Beef

Return the skillet to high heat. Do not wipe it clean—the residue is flavor.

Add the beef in a single layer. Do not crowd the pan. Work in batches if necessary. Let it sear undisturbed for 60–90 seconds, then toss. You want brown bits, not gray steam.

Cook just until no longer pink. It will finish in the oven. Remove from heat.

4. The Assembly

Preheat oven to 375°F. Butter or grease your baking dish.

Layer 1: Spread half the beef across the bottom.
Layer 2: Top with half the vegetables.
Layer 3: Lay 4 slices of provolone over the vegetables, overlapping slightly.
Layer 4: Repeat: remaining beef, remaining vegetables.
Layer 5: Top with the remaining 4 slices of provolone.

5. The Custard

In a bowl, whisk together the eggs, heavy cream, beef broth, and Worcestershire sauce. Pour this mixture evenly over the entire casserole. It will seep down through the layers, binding everything into a cohesive, savory custard.

Sprinkle the shredded provolone/mozzarella and grated Parmesan over the top.

Optional: For crunch, scatter buttered panko breadcrumbs or crushed Ritz crackers over the cheese.

6. The Bake

Bake uncovered for 25–30 minutes, until the edges are bubbling and the top is golden brown and blistering.

Let rest for 10 minutes. This is not negotiable. The casserole needs to set; cutting immediately yields a puddle, not a slice.

Three Critical Notes

1. On Cheese Authenticity:
Traditional Philly cheesesteak uses Cheez Whiz or provolone. If you want the true Wiz experience, warm ¾ cup of Cheez Whiz with 2 tbsp milk and drizzle it over the top before serving. This is heresy to some and nostalgia to others. I do not judge.

2. On Meat Selection:
Pre-shaved “sandwich steak” from the grocery store is acceptable in a pinch, but it is often cut from tougher cuts. Ribeye is worth the cost here. The fat renders into the casserole and keeps the meat moist.

3. On Peppers:
Green bell peppers are traditional. Red or yellow are sweeter and less sharp. Use what you love, but know that green is the canonical choice.

Serving & Companions

Serve this casserole with:

A simple side salad dressed with sharp vinaigrette (to cut the richness)
Crusty bread or garlic toast (to mop the plate)
Hot sauce (optional, but correct)

Leftovers reheat beautifully. The flavors marry overnight. This is a Wednesday night casserole that tastes like a Friday night cheat meal.

A Final Thought

This is not the cheesesteak your grandfather stood in line for at Pat’s or Geno’s. It does not require you to specify “wit” or “witout.” It does not drip down your wrist.

But it contains the same soul: salty beef, sweet onions, melted cheese, and the quiet satisfaction of a meal that asks nothing of you except that you eat it, enjoy it, and maybe go back for seconds.