Ingredients

Steps

1. Preheat oven to 375°F (190°C).
2. Pat the roast dry and season all over with salt and black pepper.
3. Heat olive oil in a large oven-safe skillet or roasting pan over medium-high heat. Sear the roast on all sides until browned (about 2–3 minutes per side). Remove and set aside.
4. In the same pan, add butter, onions, and mushrooms. Cook 4–5 minutes until softened. Add garlic and cook 1 minute more.
5. Stir in beef broth and wine, scraping up browned bits from the pan. Let simmer 2 minutes, then remove from heat.
6. Slice the roast horizontally nearly through (like a thick book), creating two layers without cutting all the way.
7. Spread Dijon mustard on the inside surfaces of the cut roast.
8. Layer half of the mushroom-onion mixture inside the roast, then place 4 slices of cheese over it. Close the roast, then spread the remaining mushroom mixture on top.
9. Arrange the remaining cheese slices over the top of the roast.
10. Pour the pan juices around (not over) the top, then roast in the oven 25–35 minutes until a meat thermometer reads 145°F (63°C) for medium or to your preferred doneness.
11. Remove from oven and let rest 10 minutes before slicing.
12. Slice and garnish with chopped parsley if desired. Serve with pan juices spooned over.