Place a rack in the upper third of the oven, and preheat it to 500°F.
Arrange all the vegetables in a large deep roasting pan, making sure they cover the bottom completely. Arrange the beef and veal bones and the oxtail over the vegetables, and roast on the upper rack of the oven for 1 hour.
Remove the pan from the oven, and transfer all the bones and vegetables to a large soup pot. Pour off all the fat from the roasting pan. Add 1 quart of the water to the pan, and bring it to a full boil over high heat, scraping up all the browned bits in the pan. Pour this into the soup pot.
Add the remaining 1¼ gallons water, cloves, bay leaf, peppercorns, thyme, and chile pepper. Bring to a boil, skimming off any foam that rises to the surface. Then lower the heat, stir, and cover. Simmer for 5 hours.
Remove the pot from the heat, and let the stock cool to room temperature undisturbed.
Strain the stock into a large bowl through a fine-mesh sieve or a strainer lined with a double layer of cheesecloth.
If you are going to use the stock right away, set it aside for 15 minutes to allow the fat to rise to the surface. Then degrease the stock completely, scooping the fat off with a shallow metal spoon.
If you are not going to use it immediately, refrigerate the cooled stock, and remove the hardened layer of fat from the top before you use the stock or before you freeze it.