Rub all over with kosher salt and fresh cracked pepper.
Heat ¼ cup olive oil in a large pan on medium-high heat.
Cook the roast, meat side down, for ten minutes.
Add to the pan ½ stick of butter (4 tablespoons), a small bunch of thyme, and two whole bulbs of garlic, with the cut in half lengthwise.
Continue cooking for five minutes, basting the whole roast with the butter mixture.
Place in a roasting pan, bone side down and rub garlic and herbs over the roast.
Baste every half hour for 3 ½ hours at 325 or until the center of the meat reads 125 degrees with an instant-read thermometer. Let rest for fifteen minutes and carve.
Serve with horseradish whisked with sour cream and fresh sage.
SPINACH
½ hour before the roast is finished, make the spinach.
Finely mince three shallots or one small white onion.
Sauté in two tablespoons butter until clear.
Add ¼ teaspoon salt and a few grinds of black pepper.
Whisk in 2 tablespoons flour.
Slowly whisk in ¼ cup heavy cream.
Allow to thicken, whisking frequently.
Add 1 pound baby spinach, stirring constantly until the spinach has wilted into the sauce.
