Blind bake tart shell for 10 minutes in a preheated 350 degree oven. In a mixing bowl, combine ingredients thoroughly. Pour sweet potato mixture into tart shell and return to 350 degree oven and bake for 25 minutes or until center is set.
In a food processor, combine the flour, butter and salt and pulse until the mixture is very coarse. Pour the flour/butter into a large bowl and add the ice water. Pour out onto a clean, flat surface into a large log. Using the palm of your hand, gently push and pull the mixture to form it into a dough. Do not knead, you are just slightly manipulating it.