Combine spices in a small bowl and mix well.
Prepare the backstrap by drizzling it with 1 tbsp of oil, then generously coating it with the dry rub.
Preheat oven to 375°F
Heat a large cast iron skillet over medium to medium-high heat with the remainder of the oil.
Once the oil starts to smoke, sear the meat on all sides—approximately a minute per side.
Transfer the skillet to the center rack of the oven and bake for 10-15 minutes or until the desired doneness has been achieved using an instant thermometer.
Remove it from the heat to rest for 10 minutes before enjoying it!
