Preheat oven to 325.
In a large bowl, whisk flours, tapioca starch and salt. Add coconut oil or lard and, using your fingers, gently mix and rub it in until the mixture resembles fine crumbs with a few larger pieces.
In a small bowl, whisk water, vinegar and eggs together. Pour over dry ingredients, stirring briskly with your fingers until some kind of a ragged dough starts to form.
Turn onto a working surface and gently press into a ball.
Cut into 2 halves and, while being careful not to overwork the dough, form each half into a disc. Wrap in plastic film and refrigerate until chilled, about 30 minutes (If making in advance, refrigerate the dough for up to 3 days.)
Take pastry out of the fridge at least 30 minutes prior to rolling. When the dough is at room temperature it rolls better and does not crack so much.
Roll out pastry between 2 sheets of parchment paper. Take care to flip it over from time to time and when you feel that the dough starts to adhere to the paper and not expand all that good, peel the paper off, scrape it clean with a plastic scraper if necessary and place it back over the dough.
When disk is large enough to fit into your pie dish, slide it with the parchment paper onto a plate. Peel off top paper and place pie dish over the dough. Flip the whole thing upside down so the dough falls right into the pie dish. Peel off parchment paper, and fix inevitable cracks and breakage.