Ingredients:

  • 4 large Portobello mushroom caps
  • 2 tbsp Olive Oil, divided
  • 1/2 tsp Kosher Salt (for mushrooms)
  • 1/4 tsp Black Pepper (for mushrooms)
  • 1 lb Ribeye or Sirloin steak, thinly sliced
  • 1 tbsp Unsalted Butter
  • 1 tbsp Vegetable Oil (high smoke point)
  • 1 medium Yellow Onion, thinly sliced
  • 1 Green Bell Pepper, thinly sliced
  • 2 cloves Garlic, minced
  • 1 tsp Worcestershire Sauce
  • 1/2 tsp Kosher Salt (for filling)
  • 1/4 tsp Freshly Ground Black Pepper (for filling)
  • 8 slices Provolone cheese
  • 2 tbsp Cream Cheese, softened (optional)

Instructions:

  1. Preheat the oven to 190°C / 375°F. Line a sheet pan with parchment paper. Clean the Portobello caps and gently scrape out the dark gills from the underside using a small spoon to prevent excess moisture.
  2. Brush the caps (inside and out) with 1 tbsp of olive oil. Season the insides generously with salt and pepper. Place the caps gill-side up on the sheet pan and par-bake for 10 minutes to draw out moisture. Remove and set aside.
  3. To prepare the steak, place it in the freezer for 30–45 minutes until very firm. Slice the steak across the grain into paper-thin strips (1–2 mm thick).
  4. Heat the butter and 1 tbsp of olive oil in a large skillet over medium-high heat. Add the sliced onions and peppers. Sauté for 7–8 minutes until softened and beginning to caramelise. Add the minced garlic during the last minute. Remove the vegetables and set aside.
  5. Increase the heat under the skillet to high. Add the remaining vegetable oil. Working quickly, add the thinly sliced steak (in batches if necessary). Season the steak with salt, pepper, and Worcestershire sauce. Cook for only 2–3 minutes, stirring constantly, until the meat is browned but still tender. Do not overcook.
  6. Return the sautéed vegetables to the skillet with the steak. Toss to combine the filling thoroughly and check the seasoning.
  7. Divide the steak and vegetable mixture evenly among the four par-baked mushroom caps. If using, dot small amounts of softened cream cheese over the filling.
  8. Layer two slices of Provolone cheese (or other preferred cheese) over the top of the filling, ensuring the cheese covers the entire mound. Return the stuffed mushrooms to the oven.
  9. Bake for 8–10 minutes, or until the mushrooms are tender and the cheese is completely melted and bubbly. For extra colour, broil for the last 1–2 minutes, watching constantly. Allow to rest for 5 minutes before serving.