Take the pork chops out of the fridge and let them sit at room temperature for 30 minutes.
If there's a fat cap on the chops, make some vertical cuts to prevent them from curling while cooking.
Pat the chops dry with paper towels and season both sides with salt and pepper.
Heat a 12-inch cast iron skillet over medium-high heat for 3 minutes, then add oil.
Cook the chops for 2 minutes on each side.
Add butter and garlic to the skillet.
Place rosemary sprigs on top of each chop and tilt the skillet to let the melted butter and oil gather on one side.
Occasionally spoon the butter and garlic mixture over the chops while cooking for 2 minutes.
Remove the rosemary, turn the chops, replace the rosemary, and continue cooking for 2 to 3 minutes, or until the internal temperature reaches 140ยฐF (60ยฐC).
Take the chops out of the skillet and place them on a cutting board or serving platter.
Cover with foil and let them rest for 5 minutes; the temperature will rise to 145ยฐF (62ยฐC) during this time.
Garnish with chopped rosemary before serving.