Preheat oven to 220°C (200°C fan assisted) gas mark 7. Line a large baking tray. 

Peel the sweet potatoes and cut into cubes. Add to a pan of boiling water and cook for 12-15 minutes until cooked and soft. Drain potatoes well then transfer to a large bowl, mash with the butter and put aside. 

While the sweet potatoes are cooking, prepare the kale – remove all stalks and finely chop the leaves. Cook in boiling water for 5-6 minutes until cooked through, then remove, drain well and set aside. 

Peel and finely chop the onion, peel and crush the garlic. Heat the olive oil in frying pan and fry the onion for 3 minutes, then add the garlic and fry for 1 minute more. 

Squeeze out any excess water from the kale, then add to the mashed sweet potato along with the onions and garlic and mix well until combined.  

Using your hands, pull the sweet potato mixture together into walnut sized balls (note: if you find that the mixture is a bit too runny to shape, pop it in the fridge to set for ½ hour before shaping into balls). Place on the lined baking tray and bake for 25-30 minutes.  

This recipe can also be cooked in an air fryer – line your air fryer with baking paper then add the sweet potato bites and cook at 200°C for 12-15 minutes. 

These sweet potato balls make a delicious snack or a tasty vegetable side dish the whole family can enjoy.