Add ghee to a frying pan over a medium heat with oil. Add onion
Fry until lightly golden (this will take about 10 mins, don't be tempted to turn heat up, or you will burn onions)
Add the garlic, ginger and turmeric and fry for another minute
Remove from heat and set aside to cool
Preheat oven to 200c or 400f (gas mark 4)
Add the chickpeas to a mini food processor with the egg and pulse till smooth.
Add this to a bowl with the grated sweet potato, onion, ajwain seeds
Mix to combine
Line a baking tray with parchment paper and spoon 8 equals sized amounts of the mix onto the tray.
Spray over the top with top with olive oil spray and bake in the oven for 30 mins, till golden.
Mix together the yogurt, mint, lemon juice and maple syrup and serve this on the side.