Heat your skillet over medium heat and add olive oil with a dab of butter. Put in the sliced mushrooms and cook until they’re golden brown, about 5-7 minutes. Remove and set aside for now.
Melt the remaining butter in the same skillet. Toss in finely chopped shallots and minced garlic. Stir for 2-3 minutes until fragrant and soft, but not browned.
Pour in the dry white wine and use your spoon to scrape up the flavorful bits stuck to the skillet. Simmer for 3-4 minutes to reduce the wine, concentrating its taste.
Now add the beef broth and heavy cream to the skillet. Stir everything together, then return the mushrooms to the pan. Sprinkle in the fresh thyme and season with salt and pepper. Allow the mixture to simmer for 5-7 minutes until it thickens beautifully.
While the sauce simmers, pat your steak dry, season with salt and pepper, and cook in another heated skillet. Aim for 3-5 minutes per side for medium-rare, adjusting the time for your preferred doneness.
Finally, place your cooked steak on a plate, ladle the creamy mushroom sauce over it, and sprinkle some fresh parsley on top for color and flavor. Dinner is served!