Remove rosemary leaves from the sprig. Combine with pears and sugar in a large bowl. Set aside.
Stir together oat flour, millet flour, tapioca starch, xanthan gum, and salt.
Prepare a cup of ice water.
Cut the butter into chunks then incorporate it into the flour. If you don’t have a pastry cutter (I don’t!) just use a fork. You’re done when the butter is evenly blended and you have mostly small pea size chunks of flour/butter.
Using a tablespoon, gradually add cold water, just until the dough comes together. For me, 2 T was exactly enough.
Refrigerate the dough for 20-30 min. Preheat oven to 350 degrees.
Roll out the dough to somewhere between 1/4 and 1/8 inch thickness using your preferred method. I rolled it out between two sheets of floured wax paper.
Sprinkle cornmeal (if you have it) on a baking sheet and transfer the rolled out dough to the baking sheet.
Spoon the pear mixture into the center of the dough and gather the edges up around the fruit however works best. You could pinch it together or fold small sections over.
Bake at 350 degrees until golden, about 30 minutes.