Fry the onion on a low heat with a pinch of salt, until it is soft and translucent (about 10-15 minutes)
Leave to cool until it's not too hot to touch
Set aside 1tsp of the Harissa to be added to the sauce later as well as the 25g of cheddar or parmesan and the mozzarella to be used later for the topping
Put all of the other ingredients into a large bowl and mix well with hands
Make the mixture into golfball-sized meatballs
Fry the meatballs until they are browned all over (about 5 minutes)
Add 1tsp of Harissa to your tomato veg sauce (see earlier recipe)
Transfer your meatballs to a baking dish and cover with your tomato veg sauce
Top with grated cheese (cheddar, or cheddar and parmesan), chunks of mozzarella and oregano
Bake in the oven at 200°c until the cheese is golden and bubbling (approx 40-45 minutes)
Meanwhile cook your pasta of choice
Serve the meatballs and sauce with your pasta