Method:

Set oven rack to 2/3 high and preheat oven to 500F. Wash all vegetables thoroughly, cut the leeks 3 inches into the green then in half lengthwise and wash under cold running water, then cut into thirds. Cut each onion into 8ths, slice the carrot and rough chop the celery. Cut a whole head of garlic in two.

Arrange all the vegetables in a deep roasting pan. Make certain that they completely cover the bottom. Arrange the beef and veal bones and the oxtail ontop of the vegetables then roast on the top rack of the oven for one hour. Remove the pan from the oven and transfer everything to a large stock pot. Pour off all the fat from the roasting pan, add one quart of water to the pan and bring to a full boil over high heat all thw while scraping up all the browned bits in the pan. Add this to the stock pot.

Add the remaining water to the stock pot along with the remaining ingredients. Bring to a boil and skim off any foam that rises to the surface. Lower the heat, stir, cover and simmer for 5 hours.

Remove from heat and let pot cool to room temperature undisturbed. Strain the stock through a fine meshed sieve or a strainer lined with a double layer of cheesecloth.

If using the stock right away then let sit for 15 minutes for fat to rise to the surface then scoop the fat off with a shallow spoon. Otherwise, place pot in refrigerator and cool overnight then remove hardened fat before using or freezing the stock.