Preheat oven to 375 degrees. Lightly oil large baking sheet. In bowl or food processor, mix flour, rice, flax seeds, salt, and oil until combined. Add water a little at a time until dough holds together. Pour onto floured surface and knead a few times to form a ball. Press or roll dough on baking sheet. Score into 1 1/2-inch squares. Bake 20 to 25 minutes, or until bottoms are golden brown. Cool before removing from pan.