Pork tendon.

When I was 66 years old, my daughter bought a piece of buttock meat, which weighed six pounds and six taels. These 66 pieces of meat should be cut into medium-sized pieces, just enough to fill a small bowl. It is best for the birthday girl to eat them all at once, so that they can eat smoothly. This means "sixty-six great fortunes" and good health and longevity.