Equivalents: 1 Tablespoon glace equals 5oz stock
Place rack in middle of oven, and preheat oven to 400 degrees F.
Lightly rub the marrowbones with ghee, and place in a roasting pan. Place in oven, and roast until nicely browned on all sides, turning regularly, and watching closely so they do not burn. Remove from oven, and pour any fat from roasting pan into a large stockpot. Set bones aside.
Heat pot over high heat and add all of the vegetables except the tomatoes and parsley. Cook until surfaces are browned. Add tomatoes, and cook a couple minutes longer. Transfer veggies to pan with bones.
Add a little more ghee to the pot if necessary, and brown the pieces of roast on all sides. Add the bones and veggies to the pot, and fill three-quarters full with cold water.
Heat the roasting pan on the stovetop, and add a couple cups of white wine or water to deglaze, scraping up all browned bits on the bottom of the pan, and add this to the stockpot. Add the parsley peppercorn, and bay leaves and bring to a slow boil, skimming off any scum that rises to the surface.
Add more water to bring level to 1″ from top of pot, and return to a boil. Adjust heat so stock stays at an active simmer or very slow boil (should be bubbling lightly). Simmer for at least 24 hours. While sleeping, just reduce the heat slightly, cover completely, and go to bed; top up with water, increase heat, and return to a boil in the morning.
When done cooking, skim as much grease as possible from surface, and strain the broth into another container, pressing gently on the solids to extract as much stock as possible. Discard solids.
Scrub pot well, and return to stovetop. Degrease stock as completely as possible, and return to the pot. You should have 4-5 quarts of stock at this point. Bring to a full rolling boil, and reduce by about 90% (until only 2½ cups of thick syrup or paste remains).
You only have to pay close attention to the reducing stock for about the last 15-20 minutes to ensure the pot doesn’t burn dry. Allow to cool to room temperature, and transfer to an empty ice cube tray. Refrigerate until solidified, and then freeze until needed.
To use: Break off a small chunk of the frozen glace, and stir it into any sauce to add flavor and nutrients. I will reheat the sauce and spoon over a beef fillet with a splash of balsamic vinegar..num!