3 tbsp. extra-virgin olive oil, divided
4 medium portobello mushrooms, stems and gills removed
1 onion, sliced into half moons
2 bell peppers, sliced
Freshly ground black pepper
1 lb. sirloin
4 slices provolone
1. Preheat oven to 350°. On a large baking sheet, brush mushroom caps with 1 tablespoon olive oil and season with salt and pepper. Place stem side-up.
2. In a large skillet over medium heat, heat 1 tablespoon olive oil. Add onion and peppers and season with salt and pepper. Cook, stirring often, until the vegetables are tender, about 5 minutes. Remove from heat.
3. Add remaining olive oil to skillet and increase heat to medium-high. Season steak all over with salt and pepper and cook until the steak is seared on both sides, about 3 minutes. Turn off heat and return vegetable mixture to the pan.
4. Spoon the steak mixture into mushroom caps then top with cheese. Bake until the peppers are tender and the cheese is melted, about 20 minutes.
5. Garnish with parsley and serve warm.