Preheat the oven to 180ºC. Peel and cut the red onions into thin slices. Peel and cut the sweet potato into manageable chunks, and grate using a mandolin or a normal cheese grater. Be sure to follow product safety instructions carefully if using a mandolin, to avoid injury.
Mix the mixture thoroughly
Then either:
Line a baking tray with greaseproof paper and spray liberally with low calorie cooking spray. Roll the mixture into rough balls. Place onto the baking tray so they're not touching each other. Once arranged, spray again with low calorie cooking spray
Or spray a 12 hole muffin tray with a decent amount of low calorie cooking spray, then divide the mixture equally between all 12 moulds. Press them down firmly and spray the top with more low calorie cooking spray
About half way through, turn them over using a spatula and spray again with low calorie cooking spray
Serve and enjoy however you'd like them. Sprinkle with a bit of fresh coriander, salt and pepper if you like