In a large skillet, heat a tablespoon of olive oil over medium-high heat. Add the thinly sliced ribeye or sirloin beef, seasoning generously with salt, pepper, garlic powder, and onion powder. Sauté for about 4-5 minutes, or until browned but not fully cooked. Drain excess fat and set aside to cool slightly.

Slice the potatoes, onions, and green bell peppers thinly, aiming for uniform thickness for even cooking.

Layer the ingredients in the slow cooker. Start with sliced potatoes, followed by half the cooked beef, sliced onions, green bell peppers, and half of the shredded provolone cheese. Repeat layering with the remaining ingredients.

In a mixing bowl, combine cream of mushroom soup, sour cream, beef broth, and Worcestershire sauce. Stir until smooth and well-combined.

Pour the creamy mixture evenly over the layered ingredients in the slow cooker. Cover and set to cook on low for 6 hours or high for 3 hours.

In the last 30 minutes of cooking, sprinkle the remaining provolone cheese over the top. Cover and let it continue cooking until melted and bubbly.

Once cooking is complete, gently stir the casserole to mix layers. Let sit for a few minutes before serving.