Preheat the oven to 475 degrees. Line a baking tray or two with parchment paper and set aside.

In a large bowl, mix together the potatoes, flour and salt until they form a uniform sandy texture. I usually use a pastry cutter for this.

Add the egg to the bowl and use a wooden spoon to mix thoroughly until the mixture forms a uniform, smooth dough. 

Turn the dough out onto a lightly floured surface and use a bench knife to cut into equal portions. Size and number depend on the size of flatbreads you would like! This dough will make 10 45-50g flatbreads or 5 90-100 g flatbreads.

Place one piece of dough on the parchment-lined baking sheet. Use your hands to smooth out the dough into a smooth round disk, about 1/4-1/2 inch thick.

Repeat with the remaining pieces of dough.

Use a fork to prick each flatbread in columns.

If you made 10 small breads, bake in the preheated oven for 8-12 minutes; if you made larger ones, for 12-15, until lightly golden brown. 

Let the breads cool on the pans for 5 minutes, then enjoy warm, with butter.