Preheat oven to 350F.
After the dough has chilled, remove from the refrigerator.
Lightly flour a surface and roll out the dough.
If making mini galettes, section the dough into four pieces. While working on one mini galette, place the other sections of dough in the fridge.
Roll out the dough into a rough circular shape (10-12 inch). For mini galettes, roll one section of dough out until it is a rough circle shape.
Sprinkle the galette dough with almond meal (to soak up the liquids) leaving about 2 inches around the border.
Add the peach filling on top of the almond meal.
Fold the edges of the galette and pleate them to create a free-form tart.
Sprinkle the pistachios on top of the peaches.
Brush an egg wash onto the crust and sprinkle with pearl sugar.
Place in oven for 20-30 minutes or until golden brown.