Meat Stock

Skewer the whole onion on a fork and hold it over an open flame on the stove top until its skin turns a dark gold. Alternatively, preheat a broiler (grill) and broil (grill) the onion until the edges are lightly browned.

In a deep stockpot, combine the chicken, beef, veal, browned onion, carrot and celery. Add the water and bring to a boil over high heat. Using a large spoon, skim any scum from the surface. Reduce the heat to low, cover partially and simmer for 2 hours.

Add the cheese rind and tomato and simmer, uncovered, for 1 hour longer to blend the flavors; do not overcook and do not allow to boil.

Remove from the heat and strain through a fine-mesh sieve lined with cheesecloth (muslin) into a clean container. Use immediately, or let cool, cover and refrigerate for up to 5 days or freeze for up to 1 month. Before using the chilled stock, lift off and discard the fat congealed on the surface.