Take the steaks out of the fridge about 30 minutes before cooking to let them come to room temperature.
Pat the steaks very dry with paper towels, then season generously all over with sea salt and freshly ground black pepper.
Heat a heavy-bottomed skillet (preferably cast iron) over high heat until it’s smoking hot. Add the olive oil and let it shimmer.
Carefully place the steaks in the pan (don’t overcrowd) and sear for 2–3 minutes per side for medium-rare (about 145°F) or 3–4 minutes per side for medium (about 160°F), until a deep brown crust forms.
After flipping, add the unsalted butter, garlic cloves, and rosemary or thyme sprigs to the pan.
Tilt the pan slightly and spoon the melted butter and aromatics over the steaks continuously for about 1 minute on each side.
Transfer the steaks to a warm plate or cutting board, loosely tent with foil, and let rest for 5–10 minutes.
Slice the steaks against the grain or serve them whole with your favorite sides.