1.Preheat the oven to 375°F and prepare a baking sheet by lining it with parchment paper.
2.Mix the softened butter and garlic in a small bowl, then spread evenly on the cut sides of the bread. Place on the baking sheet and cut side up.
3.In a skillet over medium heat, sauté the bell pepper and onion in olive oil until tender, about 5-7 minutes. Remove and set aside.
4.Add the thinly sliced steak to the skillet, season with salt, pepper, and Worcestershire sauce, and cook until browned, about 3-5 minutes.
5.Spread the steak and vegetables evenly over the bread. Top with shredded cheese and Parmesan.
6.Bake for 15-20 minutes, or until the cheese is melted and bubbly and the bread is crispy.
7.Slice and serve warm, garnished with fresh parsley if desired.