Place the milk, sugar, and 2 cups (460ml) water in a medium pot over high heat. Scald the milk, or bring it to just below the boiling point. In a small bowl, mix the powdered gelatin in 3 tablespoons of cold water with your fingers until completely dissolved.
While the milk is heating, peel and dice the pineapple.
Once the milk is almost boiling and giving off small amounts of steam, remove from the heat, add the softened gelatin and stir to dissolve. Add the almond extract and stir. Pour into a large baking dish (preferably 9-inch by 13-inch) lined with lightly oiled plastic wrap and chill - the liquid should come about 1 inch (2.5 cm) up the sides of the dish. The almond jello can be made 1 day in advance, covered with plastic wrap, and refrigerated.
While the jello is setting, peel and dice the mango. Combine the mango, pineapple, lychee nuts with syrup and orange segments in a deep serving bowl.
For the jicama, peel off the thick outer skin and cut the white flesh into small (1/4 inch) cubes.
Add the jicama to the other fruits. Stir gently to combine. When the almond jello is firm, cut into diamond shapes and add to the fruit cocktail. Seasoning the dessert with a pinch of salt is optional. Serve immediately.