Pat beef medallions dry with paper towels and season both sides with salt and pepper.
Heat olive oil in a large heavy skillet over medium-high heat until shimmering.
Place medallions in the skillet, ensuring they are not crowded.
Sear for 3 to 4 minutes per side until a brown crust forms and internal temperature reaches 130°F (54°C) for medium-rare.
Reduce heat to medium and add butter, garlic, rosemary, and thyme to the skillet.
Toss the garlic and herbs in the melting butter, then spoon the foaming butter over the beef for 1 to 2 minutes.
Remove beef from the pan and rest for 5 minutes before serving.