From Real Food Heals by Seamus Mullen
6 pounds grass-fed beef bones
1 pound carrots, cut into very large chunks
4 celery stalks, cut into very large chunks
2 onions, quartered
4 garlic cloves
1 cup dried shiitake mushrooms
1 (2-inch) piece fresh ginger, scrubbed and lightly crushed, plus 1/4 cup grated peeled fresh ginger
1/4 cup raw apple cider vinegar
1 tablespoon juniper berries
1 tablespoon whole black peppercorns
8 star anise pods
4 cinnamon sticks
Preheat the oven to 400°F. Fit a metal rack in a very large roasting pan or rimmed baking sheet.
Place the bones on the rack and roast, turning occasionally, until evening golden brown, 45 minutes to 1 hour. Very carefully transfer the rack to a heatproof work surface.
Transfer 2 tablespoons of the rendered beef bone fat from the roasting pan to a large stockpot and set over medium-high heat. Add the carrots, celery, onions, garlic, mushrooms, and crushed ginger. Cook, stirring occasionally, under just golden, about 5 minutes.
Add the vinegar, roasted bones, and 14 quarts cold water. Raise the heat to high and bring to a boil. Reduce the heat to maintain a simmer and add the juniper berries, peppercorns, star anise, and cinnamon sticks.
For a light broth, simmer for 4 to 6 hours. For a deeper, richer broth, go 8 to 12 hours. Using a ladle, carefully skim off and discard any foam and fat that rises to the top of the broth every 30 minutes or so.
Once you reach the depth of flavor you like, remove from the heat and strain, discarding the solids. Return the broth to the pot, season with salt, and add the grated ginger.
Drink or use immediately, or store in airtight containers in the refrigerator for up to 1 week or freeze for up to 3 months.