Step 1

In a medium bowl or large liquid measuring cup, whisk together the orange juice, orange zest, lime zest, lime juice, olive oil, garlic, oregano, salt and pepper.

Step 2

Place the pork tenderloin in a shallow dish or in a large ziplock bag and pour the marinade to cover the pork.

Step 3

Refrigerate and marinade at least 4 hours and up to 24 hours.

Step 4

Preheat a grill to medium heat (about 350 degrees F if you have a temperature gauge or thermometer) and grill the pork tenderloin for 15-20 minutes, flipping halfway through, until the internal temperature of the thickest part of the pork registers 145 degrees F on an instant-read thermometer.

Step 5

Let the pork rest for 5-10 minutes before slicing thinly. Serve the pork with warm corn or flour tortillas and whatever taco toppings you like. They are also delicious with a layer of refried beans spread on the tortillas and covered in Monterey Jack cheese (warmed in the oven until the cheese melts before adding the pork and toppings).