In a small bowl whisk together extra virgin olive oil, lemon zest, lemon juice, dijon mustard, herbs, garlic, salt and pepper.
Carefully pour marinade into a gallon size Ziploc bag, add the pork tenderloins and seal. Gently massage marinade into the pork for a few seconds to make sure it is completely covered by the marinade.
Place pork in the refrigerator and allow to marinate for at least 3 hours, over-night is even better! Occasionally turn the pork to fully marinate.
When ready to roast, preheat the oven to 400 degrees F and proceed either one of two ways:
Easiest Method: Remove pork from marinade and place in a 9"x 13" baking dish (or other any other baking dish that pork will fit into) and roast in the oven for 25-30 minutes, or until pork reaches 140 degrees when the temperature is measured in the thickest part of the tenderloin.
Alternative Method: Heat a cast iron skillet (or other oven proof/stove proof skillet) and 1 tablespoon of cooking oil over medium high heat until oil is shimmering. Meanwhile, remove tenderloins from marinade, leave any clinging herbs but try to shed as much liquid as possible to aid in browning. Place tenderloins in hot skillet, (you may have to wrap pork around the perimeter of skillet to fit) searing for about 3 minutes on each side until browned, 6 minutes total. Place skillet in oven and roast for 20-25 minutes, or until pork reaches 140 degrees when the temperature is measured in the thickest part of the tenderloin.
After removing from oven, cover with aluminum foil and allow to rest for 5-10 minutes before carving into thick slices.