Place garlic and thyme in small saucepan; add enough water to cover garlic. Bring to a simmer. Reduce heat to low; cook 10 minutes or until garlic is soft. Remove thyme; remove leaves from stems, reserving leaves.
Place garlic in mortar or small dish, reserving cooking water. Add peppercorns and reserved thyme leaves. With pestle , mash mixture with 1 tablespoon of the reserved ncooking water until of paste consistency.
Dry roast with paper towels. Spread paste lightly over all sides of the roast; place in a shallow pan. Refrigerate, uncovered, 4 hours or overnight.Remove from refrigerator 30 minutes before cooking.
Heat oven to 450 degrees. Place roast, fat side up,on rack in roasting pan. Sprinkle with salt;drizzle with oil. Bake 15 minutes. Reduce oven temperature to 300 (DO NOT OPEN OVEN DOOR). Bake an additional 1 hour 10 minutes to 1hour 20 minutes or until temperature reaches 130F for medium rare. Cover loosely with foil; let stand 20 minutes.
Meanwhile, remove drippings from roasting pan. Add broth; bring to a boil over medium heat, stirring to scrape up any browned bits from bottom fo pan. Add any accumulated juices from beef. Simmer 2 or 3 minutes. Slice roast 1/4 inch thick; serve with pan juices.
TIP: To crack whole peppercorns, place in heavy-duty resealable plastic bag. Pound with flat side
of meat mallet or heavy pan until coarsely chopped.
TIP: Drying the meat is a crucial step that accomplishes several things: Makes it easier for the paste to adhere to the meat. It ensures that the paste won't be diluted by excess moisture from the meat. It helps the meat brown.