Let’s get cooking! Follow these easy steps:

1. Preheat your oven to 375°F (190°C). Line a baking dish with parchment paper or lightly grease it.
2. Cut the tops off the bell peppers and remove the seeds and membranes. Place them in the baking dish, cut side up.
3. Heat olive oil in a large skillet over medium-high heat. Add the sliced onions and sauté until they’re soft and translucent, about 5 minutes.
4. Add the mushrooms to the skillet, cooking for another 3-4 minutes until they’re tender.
5. Push the onions and mushrooms to the side of the skillet and add the sliced beef. Cook until it’s browned, about 5-7 minutes, stirring occasionally to blend with the veggies.
6. Stir in the Worcestershire sauce, garlic powder, Italian seasoning, salt, and pepper. Mix until everything is well combined.
7. Fill each bell pepper with the beef and veggie mixture. Top with a slice of provolone cheese.
8. Bake in the preheated oven for 20-25 minutes, or until the peppers are tender and the cheese is bubbly and golden.

Remember, cooking is as much about the journey as it is the destination, so enjoy each step along the way!