Steps
1. In a blender, combine diced mango, pineapple, lemon juice, and fruit juice concentrate; blend until smooth.
2. In a saucepan, heat milk, cream, and sugar over medium heat until sugar dissolves and mixture is warm, not boiling.
3. In a separate bowl, whisk the egg yolk, then slowly temper it with the warm milk mixture while whisking continuously.
4. Return the combined mixture to the saucepan and cook over low heat, stirring until it thickens enough to coat the back of a spoon.
5. Remove from heat, stir in the blended fruit puree, and let the mixture cool completely.
6. Refrigerate the base for at least 2 hours.
7. Once chilled, churn the mixture in an ice cream maker according to the manufacturer's instructions, then freeze for another hour to set.
8. For the fruit shell, dissolve gelatin in water and let bloom for 5 minutes.
9. Warm the gelatin gently and mix with powdered sugar and a teaspoon of blended fruit puree to create a glaze.
10. On a silicone mat, spread a thin layer of the glaze into a circular shape and refrigerate until firm but pliable.
11. Once firm, gently mold the sheet into a bowl shape or cup.
12. Scoop gelato inside the fruit shell just before serving.
13. Serve immediately for a crisp shell and creamy gelato contrast.