1. Place first 3 ingredients and 1 qt. water in a large Dutch oven. Bring to a boil; simmer, uncovered, 1 hour.
2. Trim and discard thick stems from bottom of collard green leaves. Tear leaves into 2-inch pieces. Place leaves in a large bowl of water. Swish leaves around to remove any dirt. Remove leaves from bowl, and discard water. Add leaves to Dutch oven; stir. (The pot will be full, but the leaves will cook down.) Cover and simmer, stirring every 30 minutes, for 1 1/2 hours.
3. Remove ham hocks; remove meat from hocks, and chop. Discard any fat. Return meat to Dutch oven. Serve greens with a slotted spoon. Pass with Hot Pepper Vinegar. Reserve and enjoy potlikker.