Season steaks generously with salt and pepper on both sides.
Heat olive oil in a heavy skillet over medium-high heat until shimmering.
Sear steaks for 4-5 minutes per side for medium-rare, or until desired doneness is reached.
Remove steaks from the skillet and let rest on a plate tented with foil.
In the same skillet, melt 2 tablespoons of butter over medium heat.
Add sliced mushrooms and cook until browned and moisture has evaporated (about 5-7 minutes).
Stir in minced garlic, shallots, thyme, and rosemary; cook for 1 minute until fragrant.
Deglaze the pan with beef broth, scraping up browned bits.
Stir in heavy cream and remaining 2 tablespoons of butter.
Simmer for 2-3 minutes until the sauce thickens slightly.
Pour the creamy mushroom sauce over the rested steaks and serve immediately.