If using a stock pot:

1. Add the bones, apple cider vinegar, salt, and peppercorns to a large stock pot. Add about 3 quarts of cool filtered water, or just enough to cover the bones by a couple of inches. 
2. Bring to a boil and cook, uncovered, for 10 minutes. Skim off and discard any scum that has risen to the top. 
3. Reduce the heat to low and simmer, covered, for 2 hours for chicken and at least 4 hours for beef, lamb or pork.
4. Add the remaining ingredients and bring to a boil. Cook, uncovered, for 1 hour, or until the liquid has reduced by about one-quarter. 
5. Use a fine-mesh strainer to strain the broth, pressing as much liquid from the bones and vegetable as possible before discarding them. Store the broth in a glass jar in the refrigerator for up to 1 week, or in the freezer for up to 1 year. 

If using a pressure cooker / Instant Pot or other multi-cooker

1. Add the bones, apple cider vinegar, salt, and peppercorns to a large stock pot. Add about 2-3 quarts of cool filtered water, or just enough to cover the bones by a couple of inches. 
2. Secure the lid and cook on high pressure for 1 hour for chicken, or 90 minutes for beef, lamb, or pork bones. 
3. After the time is up, allow the pressure to release naturally for 10 minutes before turning the valve to venting and allowing the remaining pressure to release. 
4. Add the remaining ingredients and set the Instant Pot to sauté (or bring to a boil if using a stove top pressure cooker) Cook, uncovered, for 1 hour, or until the liquid has reduced by about one-quarter. 
5. Use a fine-mesh strainer to strain the broth, pressing as much liquid from the bones and vegetable as possible before discarding them. Store the broth in a glass jar in the refrigerator for up to 1 week, or in the freezer for up to 1 year. 

If using a slow cooker:

1. Place all of the ingredients into the insert of a slow cooker and cover with about 2 quarts of cool filtered water. Cook on low for 8-10 hours for chicken, and up to 24 for beef, pork, or lamb bones.
2. Use a fine-mesh strainer to strain the broth, pressing as much liquid from the bones and vegetable as possible before discarding them. Store the broth in a glass jar in the refrigerator for up to 1 week, or in the freezer for up to 1 year.