Fill and boil the kettle. Warm a large frying pan on a medium heat for 2 mins, then pour in 1 tbsp olive oil and add the meatballs. Gently fry for 5 mins, turning once, till browned. Use a slotted spoon to lift the meatballs out onto a plate.

While the meatballs fry, peel and finely chop the red onion. Trim the courgette and chop it into small chunks. Peel and finely grate or crush 1 garlic clove.

Add the red onion and courgette to the pan, season with salt and pepper and cook for 5 mins, stirring occasionally, till softened and golden. Add the garlic and cook, stirring, for 1 min. Pour in the passata along with 150ml hot water from the kettle and bring to a bubble. As soon as it's bubbling, add the meatballs back to the pan and turn the heat to low. Pop a lid (or a baking tray if you don't have a lid) on the pan and simmer for 10 mins.

Pour the remaining hot water from the kettle into a large pan, topping it up if needed, and bring back up to the boil. Add a pinch of salt and tip in the spaghetti. Cook for 8-10 mins till the pasta is soft, with a slight bite. Scoop a mugful of cooking water out of the pan (mind your fingers, or use a ladle) then drain the pasta.

While the meatballs are simmering and the pasta is bubbling, make the gremolata. Finely chop half of the rocket and pop it in a bowl. Zest in the lemon and squeeze in the juice. Finely grate or crush the remaining garlic clove and add that too. Pour in 1 tbsp olive oil and 1 tbsp cold water. Add a generous pinch of salt and pepper and mix well. Set to one side.

When the meatballs have cooked for 10 mins, add the remaining rocket to the pan and gently stir through to slightly wilt it. Taste and add more salt or pepper if you think it needs it. Tip the pasta into the pan and gently toss. Add a little of the reserved pasta water to loosen it if you need to.

Serve the meatballs and spaghetti on 2 warm plates. Drizzle over the zesty gremolata to serve.