Remove the meat from the fridge in time and let it come to room temperature.
Preheat the oven to 190°C.
Season the pork tenderloins with salt and pepper.
Heat the olive oil in an oven-safe skillet over medium-high heat.
Fry the pork tenderloins until golden brown on both sides, about 2 minutes per side.
Add the minced garlic and thyme leaves (if desired) and sauté for an additional 1 minute.
Cover the meat with aluminum foil in such a way that it does not dry out. Place the pan with the pork tenderloins in the preheated oven and bake for 15-20 minutes, depending on desired doneness. If necessary, use a meat thermometer to check the core temperature.
Remove the pan from the oven and add the butter. Melt the butter and baste the pork tenderloins with it.
Let the meat rest for 5 minutes before slicing. While resting, the core temperature will rise slightly - 63°C for medium rare and 70°C for medium.
Slice the pork tenderloins and serve immediately.