Pat steaks dry with paper towels. Season with salt and pepper, then let sit for 10–15 minutes.
Heat olive oil and butter in a skillet. Sear steaks for 3–4 minutes per side for medium-rare. Remove and rest.
In the same skillet, add minced garlic. Sauté for 30 seconds, scraping brown bits.
Add cream, stock, Dijon mustard, and thyme. Simmer gently until thickened.
Return steaks and coat with sauce. Garnish with fresh parsley and serve immediately.
