Roasting pork tenderloin increased the natural flavors and adding the greens and herbs make this meal very special. You should prepare the pork tenderloin to marinade overnight or at least for the day to enhance the flavors.
Place the boneless pork loin on poultry safe board and drizzle with a little olive oil and rub into the pork then season with salt and pepper.
In a small bowl or mini-chopper finely chop garlic, scallions, rosemary (remove from stem), thyme, fennel seeds and lemon zest and juice. Either set in your roasting pan and cover or place in a platter and cover then refrigerator for at least 6-8 hours or overnight.
When ready to roast preheat oven to 325° F. Place pork on a rack in your roasting pan. Add the fennel, celery, carrots and onions around the pork. Drizzle with a little olive oil the season with salt and pepper. Pour wine and chicken broth into the pan under the rack.
Roast until the internal temperature reaches 153° F from the center of the pork by using a meat thermometer.
Remove from roasting pan along with the vegetables onto a plate and tent with foil to let rest. The roast will continue cooking. If your roasting pan is stove save place over medium heat and bring to a boil while whisking. Add in butter and continue whisking. Whisk in arrowroot powder.
Either pour gravy into a bowl or pour over sliced pork tenderloin.