To make a New York strip loin roast, begin by mashing 4 cloves of garlic, 4 thyme leaves, 4 teaspoons of olive oil, 4 teaspoons of salt and 1 1/2 teaspoons of black pepper. Rub this mixture over a 4- to 5-pound strip loin roast, and keep it in the fridge overnight. Roast with the fat side up for 25 minutes at 400 degrees F. Reduce the temperature to 350 degrees, and roast to the desired doneness.
Alternatively, make a New York strip roast with vegetables and a mustard cream sauce. Prepare the sauce by combining 1/2 cup of creme fraiche, 2 tablespoons of Dijon mustard, 1 teaspoon of fresh lemon juice and kosher salt to taste. Cover and chill this mixture.
To prepare the roast, season a 3-pound boneless strip loin with a mixture of 1 tablespoon of unsalted butter, 2 cloves of garlic, 2 teaspoons of fresh rosemary, 3/4 teaspoon of kosher salt and 1/2 teaspoon of cracked black pepper. Let it stand for one hour while you prepare the vegetables.
In a large bowl, combine 1 pound of halved mushrooms, 1 pound of sliced turnips, 12 ounces of sliced carrots, 12 ounces of sliced celery, 5 sliced shallots, 5 tablespoons of olive oil, 1 1/2 tablespoons of fresh rosemary and kosher salt to taste. Stir well, and transfer the vegetables to a baking sheet. Place the meat in a separate baking dish, and bake the two dishes for 20 minutes at 450 degrees Fahrenheit. Reduce the temperature to 350 degrees, and continue roasting until the vegetables are tender and the meat reaches 130 degrees Fahrenheit for medium rare.
Transfer the roast and vegetable mixture to a platter. Serve with the mustard dipping sauce on the side.