In a large mixing bowl, combine the olive oil, paprika, oregano, chili powder, coffee powder, lime juice, salt, and pepper.
Mix until well blended.
Add the pork tenderloin and toss to coat well.
Cover and place in the refrigerator for at least 2 hours. Toss the pork a few times to coat well.
Place a large non-stick skillet over medium high heat.
Spray the pan lightly with olive oil. When the pan is hot add the pork tenderloin.
Cook for about 2 minutes on each side until well seared.
Cover the pan and reduce the heat to medium. Cook for about 15 minutes.
Turn the pork at least twice. Adjust the heat to keep the pork from burning.
While the pork is cooking place the chicken stock in the bowl with the marinade and whisk to mix the remaining spices into the liquid.
When the pork is at 140° F internal temperature add the stock and marinade mixture to the pan.
Turn the pork in the stock for about one minute and then remove the tenderloin to a cutting board.
Reduce the stock by about half and then add the butter.
Whisk until the sauce thickens slightly and turn heat to low.
Slice the pork and place on plates.
Top with the sauce and serve.
