Whisk together the olive oil, red wine vinegar, parsley, rosemary, grain mustard, dry mustard, garlic, salt, pepper lemon juice. Pour over the tenderloins in a plastic bag and allow to marinate in the fridge for anywhere between 1 hour and overnight.
Preheat the oven to 375 degrees F.
After marinating, sear the tenderloins in the butter and olive oil. Add the root vegetables and baste them in the sauce. Cover and place in the oven for 25 minutes.
Slice the pork into medallions and serve with the sauce from the bottom of the pan. Serve with hot buttermilk biscuits.
A viewer or guest of the show, who may not be a professional cook, provided this recipe. It has not been tested for home use.