Combine shredded jicama, sherry and water in a small saucepan. Bring to a boil and reduce heat. Cover and boil gently 45 minutes, or till most of liquid has evaporated. Drain thoroughly. Set aside
Mix 3/4 cup Splenda, flour and salt in a medium saucepan. Beat egg yolks and 1 cup milk in a small bowl. Stir into Splenda mixture. Add remaining 1 cup milk and cinnamon. Stir over medium heat until mixture boils and becomes very thick. Remove from heat and cool slightly.
Mix the cooked jicama with the custard mixture.
Pour mixture in pre-baked pie shell. Sprinkle lightly with 1/4 teaspoon ground cinnamon and 2 teaspoons sugar. Broil pie 3 inches from heat 3 to 4 minutes, or until sugar mixture is melted and bubbly. Watch carefully and do not let crust burn. Cool pie slightly. Serve warm or at room temperature .
OPTIONAL: Serve with dollop of Fat Free Topping.