1. Preheat oven to 200°C
2. Heat olive oil in a pan on medium to high heat. Add the meatballs and cook, turning them to cook all sides for 5 minutes or until browned all over. Remove from pan and set aside.
3. Add garlic and onion to pan and cook, stirring for 5 minutes, until slightly soft.
4. Add tomato passata to the pan, season with salt and pepper and bring to a simmer.
5. Return meatballs to the pan and top with mozzarella cheese and oregano.
6. Bake in oven for 10 minutes, until meatballs are cooked through and cheese is bubbling.
7. In the meantime, blend the kale pesto ingredients in a food processor.
8. Serve meatballs and top with kale pesto, parmesan and fresh basil.