Pre heat oven to 190c /375f / Gas5. Pierce each potato with a fork several times and place in a baking tray. Bake for 45 mins (or until they feel soft to squeeze)
In the last 15 mins of cooking, heat the oil in a pan over a medium heat. Add the onions and cook for 5 mins (until soft and turning translucent). Add the garlic and cook for a further min.
Stir in the smoked paprika and cumin, cook for a further minute, before adding the tomatoes and chickpeas. Stir.
Reduce the heat to low, cover and allow to simmer for approx. 10 min.
Remove the potatoes from the oven, allow to cool slightly and then cut in half lengthways.
Spoon out the flesh (leaving a thin layer of the sweet potato inside) and add the flesh to a medium bowl.
Place the skins back onto the baking tray face up, drizzle with olive oil and bake for 8 minutes.
While the skins are cooking, mash the sweet potato flesh and mix together with the chickpea mixture.
Remove the skins from the oven and fill each one with the mixture.
Add a spoon of greek yoghurt to each potato (optional)