On a baking sheet, spread out the pork hocks and necks in an even layer. Roast until golden brown, about 40 minutes.
In a large stockpot or slow cooker, combine the hocks, necks, and hooves. Cover with the water, and bring to a boil over medium-high heat, then reduce the heat to medium. If using a slow cooker, set the temperature to high. When broth begins to boil, reduce slow cooker temperature to low. Skim off the fat and scum that rises to the top and discard. It usually takes about 1 hour for the scum and impurities to rise.
Add the remaining ingredients and continue to simmer for 15 to 20 hours, adding water as necessary to just keep the bones covered – this is key to yielding a gelatinous bone broth. If using a stockpot, be vigilant about checking the water level. We’ve burned plenty of batches, and recommend using alarms to prevent burning your precious broth.
Gently strain or ladle the liquid through a fine-mesh strainer into a container. Fill your sink with ice water. Place the container of broth in the ice bath to cool for about an hour. Use the broth right away, or cover and refrigerate for up to 1 week, or freeze for up to 1 year.