Line an oven tray with baking paper.
In a medium bowl mix together the oat flour, rice flour, ginger and salt.
In a large bowl, cream together the butter and sugar until blended and somewhat fluffy. Add the flour mixture, stirring until combined (it may look slightly crumbly).
Roll the dough out between two pieces of baking paper until just over a 0.5cm thick. Transfer this to the fridge to chill for at least 1 hour or up to 1 day.,
Preheat oven to 160C.
Cut shapes out of the pre-rolled dough and bake in the preheated oven for 12 to 15 minutes until shortbread is cooked through and pale golden. Cool completely on tray.
*You can grind your own oat flour in a high-speed blender, food processor, or coffee grinder. It will take about 1-1/2 cups of rolled oats