Place the Javelina in a re-sealable plastic food storage bag with all of the ingredients save for 2 tablespoons of the olive oil. Refrigerate for 6 hours.
Remove the meat from the refrigerator and allow to come to room temperature for 20 minutes.
Tie the backstraps with kitchen twine so they are uniform in thickness. If you are using tenderloins, tie them together using the same method.
Preheat the oven to 350 degrees F.
Heat a large skillet over medium-high heat. When hot, add 2 tablespoons of olive oil. Sear the tenderloins until golden brown on all sides, about 4 minutes. Transfer the skillet to the oven and cook for 12-15 minutes longer, until they reach an internal temperature of about 140 degrees F.
Remove from the heat and set on a plate. Cover with tin foil and let sit for 20 minutes before slicing to serve.