Gather all the ingredients. Wash all the fruit.
Cut the fruit into sections and remove their pits. I usually cut the peaches and nectarines into 8 sections and the plums into 4 sections. I cut them as I would a pie: using a sharp knife and cutting vertically from top to bottom into sections. I then remove the sections away from the pits. However, you can also remove the pits and then cut into sections.
Put all the fruit into a non-reactive bowl. Mix the tapioca flour or cornstarch with the sugar and add to fruit. Add seasoning and the lemon juice.
Let the fruit sit about 15 minutes at least so the flavors mix a bit. During this time you can preheat the oven and roll out your dough.
Preheat oven to 180°C / 350°F. When the dough is placed into your pie pan, fold over the top of the crust into your preferred pattern. I usually just crumple the dough using my forefinger and thumb going around the top edge. Make sure you prick the bottom of the pie crust several times. Brush the crust with egg white, as this will help prevent the liquid and fruit from making the crust soggy.
Place the fruit into your pie tin. You can either do this in attractive manner by making a design or simply by pouring the fruit in. Either way, I usually fix the fruit a little so fruit is evenly placed around the pie and it looks as even as possible.
Put little pieces of butter (fingertip size) randomly on top of the pie. If you prefer you can push them down a bit into the fruit.
Place in the top half of the oven for approximately 45 minutes or until the crust is golden and the fruit looks cooked. I usually turn my pie half way and then gauge my time from how it looks at that moment. Sometimes if the crusts looks like it is browning too early, I will place at this time a sheet of foil loosely on top of the pie (not folded down onto the pie) to help prevent the crust from burning before the fruit filling is done.
Remove the pie from the oven and let cool before serving. It can be served warm (not hot) with ice cream or at room temperature however you wish. The pie might be more liquidy if you serve it warm than if it is cooled completely.