This recipe is from Jacques Pepin's Fast Food My Way. It's such a simple but elegant (and tasty) dessert, and requires no cooking. He says that panachee is a mixture of two or more ingredients with different colors, flavors, or shapes. This recipe is very flexible. You can substitute similar ingredients as noted. The berry puree can be made a few hours ahead of time, and the assembly, which only takes a few minutes, can be done just before serving.