EVOO Extra Virgin Olive Oil, for drizzling
Kosher salt and pepper
1/3 cup dry sherry
4 tablespoons butter, softened
2 tablespoons finely chopped parsley
1 tablespoon thyme, finely chopped
A handful of dried porcini mushrooms
1 cup beef stock
1 shallot, finely chopped
2 tablespoons aged balsamic vinegar
1/4 cup Worcestershire sauce
2 tablespoons dark brown sugar
2 teaspoons coarse black pepper
1 cup good quality ketchup
1 large rib eye steak, 1 1/2- to 2-inches thick
Preheat oven to 425F. Drizzle garlic bulbs with oil and season with salt and pepper. Wrap tightly in foil and roast to tender, 45 minutes. Reserve 1 head for the Swiss Chard Au Gratin. Add cast-iron pan to oven to preheat.
Squeeze cloves from remaining 2 bulbs garlic into the bowl of a food processor. Add sherry, butter, parsley, thyme, salt and pepper. Pulse process into a paste and reserve.
For the steak sauce, simmer porcini in stock to reconstitute and soften. Let reduce, 15-20 minutes, then transfer to a food processor and pure. In a small pot over medium heat, saut shallots and 2 cloves finely chopped garlic in a drizzle of EVOO to soften. Add pured porcini stock, balsamic, Worcestershire, brown sugar, pepper and ketchup, and simmer to thicken 20 minutes over low heat.
Bring meat to room temperature, 30 minutes to 1 hour. Pat meat dry and rub with a drizzle of oil. Season aggressively with salt and pepper. Remove hot cast-iron skillet from oven and place over medium-high heat. Add steak to hot pan and brown 3 minutes on each side. Transfer to oven and cook 6 minutes more for medium-rare, turning once. Remove meat and let rest before carving.
Slather steak with garlic sherry butter, slice and top with steak sauce. Serve Swiss Chard Au Gratin alongside.