Bring cream and sugar to boil in large saucepan over medium heat, whisking until sugar dissolves. Increase heat and boil 3 minutes, stirring constantly and adjusting temperature to avoid boiling over. Remove from heat; stir in juice and peel. Let stand 10 minutes. Stir again to blend (mixture may begin to thicken). Divide mixture among six 3/4-cup custard cups (cups will be only 2/3 full). Chill overnight to set. Garnish with fresh clementine segments.