Peel and cut 8-10 mangos into chunks and puree them in a blender. Add 2 tablespoons lemon juice and cook in a large, heavy pot until the mango butter is thick. It usually takes about an hour and you must keep stirring to prevent burning or sticking.
Line a large baking tray with saran wrap and pour the mango butter in an even layer 1/8 inch thick. Bake at 150 degrees about 8 hours or until mango pulls away easily from the saran wrap. Remove from the oven and allow to cool before rolling up, with or without the wrap.
The mango can be used in recipes the same way dried fruit is used or eaten as a snack. It keeps 6 months in the refrigerate, indefinitely in the freezer.