Place peppercorns in a small plastic bag and crush with a mallet. Add crushed peppercorns, crumbled bay leaf, salt, smashed roasted garlic cloves, dried thyme, dried oregano and dried rosemary to a small bowl and blend until it forms a paste like substance. Stir in oil. Rub the paste all over the roast. Transfer the roast to a roasting pan, bone side down and let marinate in herbs in the refrigerator for 8 hours. Remove roast from refrigerator 1 hour before cooking. Preheat oven to 450 degrees F. Roast meat for 20 minutes. Reduce temperature to 350 degrees F. and continue to cook for 1-1 3/4 hours or until internal temperature reaches 110 degrees. Transfer roast to carving board and cover with foil. Roast will continue to cook and will reach 130 degrees F.
For jus: Place roasting pan on top of stove over medium-high heat. Add broth, rosemary and thyme sprigs and smashed garlic clove. Deglaze pan, scraping up browned bits. Reduce heat to simmer for 10 minutes. Season to taste with salt and pepper. Thinly slice roast and serve with jus.
To roast garlic: Cut 1/4" off the top of a head of garlic and rub all over with olive oil. Wrap garlic head in foil. Roast in oven at 350 degrees F. for 45 minutes.