Wash the leg slice and bones, peel and halve the onions, clean the carrots, halve the leek lengthways and wash. Cut the vegetables into large pieces. Cover all ingredients with water in a large saucepan without a lid (covered the broth would become cloudy) bring to the boil and then simmer over medium heat for at least 1 hour. Skim off the foam that forms and, if necessary, top up with water.
Then remove the stock from the hob and pour it through a fine sieve into a container.
The meat broth can be used as a basis or ingredient for many dishes.