Begin by bringing the beef to room temperature. This helps it cook evenly. Meanwhile, preheat your oven to 220°C (425°F).

Next, season the beef generously with kosher salt and freshly cracked black pepper.

In a hot skillet, add the vegetable oil. Once shimmering, carefully place your seasoned beef in the pan. Sear each side for about 2–3 minutes until you achieve a beautiful brown crust. This step is crucial for flavor.

While the beef is searing, whip up the garlic-thyme butter. In a bowl, combine softened butter, grated garlic, thyme leaves, cracked black pepper, and optional lemon zest. Mix until well combined.

Once the beef is seared, take it out of the skillet and spread the butter slather over the top.

Transfer the beef to a roasting pan or a lined baking sheet. Insert a meat thermometer into the thickest part of the meat. Roast in the preheated oven for about 20–25 minutes or until the internal temperature reaches 60°C (140°F) for medium-rare.

While the beef is roasting, use the skillet you seared the beef in. Add sliced mushrooms and allow them to cook until golden brown, about 5–7 minutes.

Next, add minced garlic and shallots, sautéing for another 2 minutes. Pour in the Marsala wine, letting it reduce for about 5 minutes before adding chicken stock and heavy cream. Simmer until thickened, about 10 minutes. Finish with thyme and black pepper for flavor.

Once the beef is out of the oven, cover it loosely with foil and let it rest for 10–15 minutes. This allows the juices to redistribute.

After resting, slice the beef and serve with the creamy mushroom sauce drizzled on top.