This is the ultimate comfort food mash-up, bringing the iconic flavors of a Philly cheesesteak into a warm, cheesy, and effortless pasta bake. My secret is browning the beef and onions first to build a deep, savory base that the slow cooker melds into pure magic.

This clever casserole captures everything you love about a Philly cheesesteak—tender beef, sweet bell peppers, and caramelized onions—all folded into pasta and melted cheese. The slow cooker does the heavy lifting, making the beef incredibly tender and allowing the flavors to meld beautifully over hours. For the best results, I always recommend using a reliable quality slow cooker that maintains a steady, low heat.

Ingredients

• 1 lb (450g) ribeye steak, thinly sliced (or sirloin)
• 1 tbsp olive oil
• 1 large yellow onion, thinly sliced
• 1 green bell pepper, thinly sliced
• 1 red bell pepper, thinly sliced
• 3 cloves garlic, minced
• 1 (12 oz / 340g) package penne pasta
• 3 cups beef broth (low-sodium)
• 1 (10.5 oz / 298g) can condensed cream of mushroom soup
• 1 cup shredded provolone cheese
• 1 cup shredded mozzarella cheese
• 1/2 cup shredded Parmesan cheese
• 1 tsp Worcestershire sauce
• 1/2 tsp salt
• 1/4 tsp black pepper
• 1 tbsp chopped fresh parsley (for garnish)

Instructions

1. Heat olive oil in a large skillet over medium-high heat. Add the thinly sliced onion and bell peppers. Cook, stirring occasionally, for 6-8 minutes until they begin to soften and get light brown edges. Remove to a plate.
2. In the same skillet, add the sliced beef in a single layer if possible. Cook for 2-3 minutes per batch, until just browned but not cooked through. Do not crowd the pan. Transfer browned beef to a plate.
3. In a 6-quart (or larger) slow cooker, whisk together the beef broth, cream of mushroom soup, Worcestershire sauce, salt, and pepper until smooth.
4. Add the uncooked penne pasta, the browned beef, and the sautéed peppers and onions to the slow cooker. Stir gently to combine and ensure pasta is mostly submerged in liquid.
5. Cook on LOW for 3.5 to 4 hours. The pasta should be tender and the beef very tender. Do not stir too frequently, especially in the first hour, to prevent the pasta from breaking down too much.
6. Once cooked, gently stir in the provolone, mozzarella, and Parmesan cheeses until melted and creamy. Let it rest, covered, for 10 minutes before serving to allow the sauce to thicken slightly.
7. Serve hot, garnished with chopped fresh parsley.