Preheat oven to 400 degrees, line baking sheet(s) with aluminum foil, and spread bones out in a single layer.

Roast for one hour, turning after about 40 minutes. Bones will get dark, but shouldn’t burn.

Transfer bones to a stock pot, add apple cider vinegar, onion, garlic, and peppercorns. Cover with water. Bring to a boil. Cover the pot, lower the heat, and simmer for 3-4 days. Or use a crockpot on low. Pressure cooking for a couple hours also makes a good broth.

Strain broth into a container set into a large bowl of ice to cool quickly. Can be frozen in canning jars (fill only 2/3 to allow for expansion). Sip 4-6 ounces each day, or use as base for soup or stew.