Pre-heat oven at 200C and line a baking tray with greaseproof paper (I also brushed it with a little oil).
Place the potatoes inside a microwave safe bag and tie a knot. Pierce a hole with your finger and cook in a microwave for approximately 12 minutes. (The exact time may vary depending on your microwave and size of potatoes so cook until you can easily place a knife through them). You can also boil until tender.
Allow to cool, then peel the skin off (you can easily peel with your fingers) and cut into rough chunks. Place in a bowl.
Add the remaining ingredients to the bowl. Using your hand, combine all of the ingredients together until they are well mix and incorporated. Taste for salt/chilli and adjust accordingly.
Now, very lightly grease your hands with a very small amount of oil. Now get a walnut size amount of the sweet potato mixture. Roll into a ball and press down slightly so a patty forms. The width should be about 3-4" wide. Place on the baking tray and repeat with the remaining mixture.
If you find the mixture is difficult to roll into a smooth patty, you can add a little more gram flour to help with binding.
Bake for 10 minutes then turn over and cook for a remaining 10 minutes. Enjoy!