Mix the rice flour, cornflour and cardamom and set aside.Tip the icing sugar into a sieve to sieve straight onto the butter.
Cream the butter with a wooden spoon for 20 seconds to lighten it (Stir vigorously). Add icing sugar and stir vigorously with the wooden spoon for about 30 seconds.
Add the egg and rose water and stir well once again to mix until you have a smooth mixture.
Fold in the flours and cardamom, mixing well. You'll have to use your fingers to bring it all together but don't knead the dough. The dough will be pretty sticky. If it sticks to your hands too much, dust your hands with some icing sugar.
Clean your hands, dust your work surface with a tiny amount of icing sugar and roll your soft dough into 2 logs. Wrap well with a clingfilm or your usual plastic wrap and chill in the fridge for 1 hour.
When you're ready to bake, preheat the oven to 160˚C/320°F, and grease 2 baking sheets or trays.Unwrap 1 log and using a sharp knife, quickly slice your log into little discs, measuring about 2cm thick (about 0.8 inch).Keep the second log in the fridge until you're ready for it.
Using your hands, form little balls with the dough, press them slightly and place on the baking sheet, giving an inch between each cookie. Work quickly, so the dough doesn't warm up too much.
You can leave your cookies as they are, unpatterned.Or, using the side of a fork, or a cookie stamp, form grooves or any pattern on your cookies.
Sprinkle some poppy seeds or ground rose petals in the middle of each cookie.Do the second tray, if you want/can bake 2 trays at once.
Bake for 15 - 18 minutes until your cookies are a pale, beige colour. 2 trays - 1 on the middle shelf, 1 lower. The lower shelf may need 2 minutes extra.Repeat with the rest of the dough until it's all done.