In a large saucepan, place all of the ingredients, except the chopped chocolate bar, and simmer over low heat for 5-7 minutes to thoroughly dissolve the agar-agar flakes. Remove from heat and set aside to cool. Freeze the mixture in an ice-cream maker per machine instructions. Transfer to an airtight container, fold in the chopped chocolate bar, and allow to freeze 20 minutes or more before serving.

Or if you don't have an ice cream maker, pour the mixture into a large shallow pan, and place in the freezer. Stir the mixture every hour or so to give it a smooth texture. When completely frozen, remove it from the freezer, and allow it to sit at room temperature for 15 minutes. Transfer the mixture to a food processor and process until smooth. Transfer the mixture to an airtight container and fold in the chopped chocolate bar. Return the mixture to the freeze and freeze until solid. Serve as an accompaniment to cakes, pies, desserts, or as a refresher.

Yield: 1 1/2 Quarts