Preheat the oven to 220°C / 200°C fan / gas 6.
For the meatballs, mix the pork with the breadcrumbs, onion, garlic, lemon zest, herbs and egg. Season to taste with salt and freshly ground black pepper. Roll the mixture into walnut sized balls, setting aside on a large plate as you go. Slightly damp hands will make this a less messy task, although if you have time, this is a job children love to get involved in. Just try to help them get all the meatballs similar in size so they cook evenly.
Cut the squash up into 3-4cm chunks, leaving the skin, and spread it out into a large roasting tray. Tuck in the cloves of garlic and drizzle over most of the oil, and season with a little salt and pepper. Roast in the hot oven for 15 minutes.
Remove the pan from the oven, add the tomatoes and give them a good mix with the squash, then spread out the meatballs over the top. Return to the oven for 15 minutes.
Blanch the Tenderstem in boiling water for 2 minutes before draining well. Add to the roasting pan, stirring to mix and return to the oven for 10 minutes. Squeeze over the lemon juice and scatter with the parsley and parmesan (if using) before taking to the table in the tray. Serve with plenty of crusty ciabatta to mop up the juices.
Cooks tip: For a different flavour, why not swap the oregano and thyme for a pinch of smoked paprika, coriander and cinnamon in the meatballs?
Recipe courtesy of Tenderstem Broccoli