Combine Brasilia Blueberry with blood orange juice and stir well. Add agave and lemon juice to elevate the level of sweetness and acidity. Rub mint and tarragon between fingers to bring out the flavor of the herbs. Add to liquid and let stand for 30 minutes. Pour into a shallow pan or sheet tray and freeze for 2 hours. In thirty-minute intervals scrape pan to keep liquid from freezing solid. Serves 6.