Preheat oven to 400*
Pat pork tenderloin dry with paper towels and season pork liberally with salt and pepper on all sides
Heat a 12-inch cast iron or nonstick oven-safe skillet over medium high heat and add 1/2 tablespoon of avocado oil. Once oil is hot but not yet smoking, add the pork and let cook undisturbed about 3-4 minutes or until a nice brown crust starts to form.
Continue to brown the pork on all sides. Meanwhile, in a medium bowl, toss the baby potatoes with the remaining avocado oil and season with salt and pepper.
Once the pork tenderloin is browned on all sides, add the potatoes to the skillet and roast in the oven for about 15 minutes or until the internal temperature of the pork registers 140*
Once the pork tenderloin reaches 140* remove it from skillet and set on a cutting board to rest for about 15 minutes. While the pork rests, turn the oven up to 450* and continue to roast the potatoes until fork tender, about 15 minutes.***
After 15 minutes, thinly slice the pork and top both the pork and potatoes with the citrus herb sauce.
In a food processor, pulse together the parsley, oregano, scallion and lemon zest until finely chopped. Add in lemon juice, red pepper, 1/4 teaspoon of salt and olive oil and process until well combined. ***
**I recommend serving this with some greens tossed with olive oil, lemon juice and salt or your favorite salad. If you would like to roast a veggie side, you can throw seasoned, chopped veggies of your choice into the skillet with the potatoes after you remove the pork tenderloin.
***if you do not have a food processor, you can also make this sauce by finely chopping the herbs and scallions and stir together with the remainder of the sauce ingredients. The flavor will intensify as it sits.
The citrus herb sauce can be made up to 2 days ahead of time if stored in the refrigerator - if making ahead, allow 30 minutes for sauce to come to room temperature before serving as olive oil will congeal when cold.