Prepare the topping. In a medium saucepan, combine mango, apricot preserves, water, lime juice, and potato starch. Mix together and cook over medium heat until thickened and mango chunks are soft. If mixture gets too thick and starts to stick to the pan, add more water 1 tablespoon at a time. Remove from heat and puree in a food processor until smooth, or use animmersion blender.