Preparations: Preheat the oven to 350°F/ 180°C. Place a long piece of aluminum foil on a baking sheet; it should be about double as long as the baking sheet, as you will have to wrap it over the turkey tenderloins.
Seasoning: Dry the meat with kitchen towels and rub them with salt and pepper on both sides.
Mix: Grate the garlic. Place it in a small bowl, add the Italian seasoning and mix well. Set aside.
Sear: Heat the oil in a large skillet. Brown the tenderloins for about 2 minutes on each side or until deeply golden. Lift them with tongs and place them on the prepared baking sheet.
Top: Divide the seasoning mixture between the two pieces of turkey and press the seasoning all over their upper side. Cut the butter into smaller parts, about 8-10 pieces. Place them on top of the turkey fillets.
Bake: Wrap the turkey in foil. Bake until the turkey breast reaches an internal temperature of 160°F/ 72°C - this will take about 30-35 minutes, but check after 25 minutes already. Check with an instant-read thermometer (Note 2).
Rest the meat for 5 to 10 minutes, loosely wrapped in the foil. During this time, the internal temperature will reach 165°F/ 75°C, which is the recommended internal temperature for turkey.
Slice the meat, place the pieces on a warm serving platter and spoon all the buttery pan juices on top. Don’t skip this step; the juices have a fantastic flavor, and they will make the meat even juicier. Serve immediately.