Prep the peppers: Heat the oven to 400°F (200°C). Halve the bell peppers lengthwise and remove seeds and membranes. Brush the insides lightly with olive oil and sprinkle with a pinch of salt and pepper. Place cut-side up on a baking sheet and pre-bake for 8–10 minutes to soften slightly.

Sauté the veggies: While the peppers par-bake, heat a large skillet over medium-high heat. Add olive oil and butter. Sauté the onion and the sliced green pepper with 1/2 teaspoon salt and 1/4 teaspoon black pepper until tender and lightly browned, about 8–10 minutes. Stir in the minced garlic for the last 30 seconds. Transfer to a bowl.

Cook the steak: Increase heat to high. If the pan is dry, add a drizzle of oil. Add the shaved beef in a single layer (work in batches if needed). Season with remaining salt, pepper, smoked paprika, and garlic powder. Sear 1–2 minutes per side until just cooked through. Don’t overcook—it will bake again.

Add flavor: Return the cooked onions and peppers to the pan with the steak. Stir in the Worcestershire sauce and toss to combine. Taste and adjust seasoning.

Layer with cheese: Remove the peppers from the oven. Place half a slice of provolone in each pepper half. Spoon the steak mixture evenly into the peppers, then top each with another half to full slice of provolone, depending on how cheesy you like it.

Bake to melt: Return the stuffed peppers to the oven and bake for 8–12 minutes, until the cheese is melted and lightly golden around the edges.

Finish and serve: Garnish with chopped parsley if you like. Let them rest for 3–5 minutes so the juices settle, then serve hot.