Preheat oven to 450 degrees F (204 C) and place a heavy roasting pan or 2 in the oven.
When the pan is heated, add the oil and the veal bones tossing lightly to coat.
Place the pan in the preheated oven and roast the bones stirring occasionally until just golden brown. Remove bones and set aside.
In the same roasting pan, brown the onions and carrots. Continue to cook until the vegetables are golden brown. If the sucs at the bottom of the pan are browning too rapidly, add a little cold water to the pan.
In a large sautoir or rondeau, heat some vegetable oil and sweat the leek greens and celery until they start to develop color. Add the tomato paste and continue to cook until the some more color develops.
Pour off the fat from the roasting pan and deglaze the pan with a wooden spoon and some water. Pour these juices into the large stockpot. Do not use if the pan scrapings are too dark or you will have a burnt tasting stock.
Place the bones and vegetables in the stock pot and cover with cold water. Bring up to a boil.
Reduce to simmer and skim well.
Add the tomatoes and garlic, and bouquet garni.
Simmer low for 8-12 hours, skimming often and checking the activity of the water. Do not allow to boil, but try to keep the water moving through a low simmer. If too much evaporation occurs, add some cold water to the pot to cover the bones.
Strain the stock carefully and cool in an ice bath skimming well. Refrigerate or freeze until ready to use.