For the paste:
1 whole head of garlic
3 tablespoons plus 1 teaspoon extra-virgin olive oil, divided
1 beef tenderloin, 3-1/2 to 4 pounds
3 tablespoons whole pink peppercorns
2 tablespoons chopped fresh rosemary
2 teaspoons kosher salt
1/2 teaspoon freshly ground black pepper
1. To make the paste: Remove the loose, papery outer skin from the head of garlic. Cut about 1/2 inch off the top to expose the cloves. Place the garlic head on an 8-inch square of aluminum foil and drizzle 1 teaspoon of the olive oil over the cloves. Fold up the foil sides and seal to make a packet, leaving a little room for the expansion of steam. Grill over Indirect Medium heat until the cloves are soft, 30 to 45 minutes. Remove from the grill and allow to cool. Squeeze the garlic from the individual cloves into a small bowl. Add the remaining 3 tablespoons of olive oil and mash the garlic and oil together with a fork to form a paste.
2. Trim the tenderloin of any excess fat and silver skin. Spread the paste on the tenderloin, rubbing it into the meat.
3. In a small bowl combine the peppercorns, rosemary, salt, and pepper. Mix well and press into the paste on the top and sides of the tenderloin.
4. Allow the tenderloin to stand at room temperature for 20 to 30 minutes before grilling. Grill over Indirect Medium heat until the internal temperature reaches 135 F for medium rare, 30 to 40 minutes.
5. Remove from the grill and allow to rest for 5 to 10 minutes. The temperature will rise 5 F to 10 F during this time. Cut into 3/4- to 1-inch slices and serve warm.