Leftover bones from roast duck
Pan drippings
Duck giblets (gizzard, heart, neck, skinned/peeled duck feet)
1 tsp salt (or to taste)
6 cups (1200 ml) water
½ tsp vinegar
Cook everything in a tightly covered heavy stock pot over medium heat until it reaches a full rolling boil, then reduce heat and allow to simmer for 1 ½ hours.
1 ½ hours
Drain and reserve liquid, discarding bones and reserving any meat.