1. Stud the onion with the cloves, then combine all the ingredients in a large saucepan or small stockpot with 10 cups water. Turn the heat to medium-high and bring to a boil. As soon as bubbles start coming to the surface, adjust the heat so that the mixture cooks at a steady simmer, but not a rapid boil.

2. Cook for about 1 ½ hours, stirring occasionally. Cool slightly, then strain, pressing lightly on the solids to extract some of their liquid (don’t press too hard or you will cloud the mixture unnecessarily). Use immediately, or refrigerate for up to 3 days, or freeze for up to 3 months.