Heat your oven to 200°C/Fan 180°C/Gas 6. Coarsely grate 2 of the courgettes. Put them in a sieve with a pinch of salt. Squeeze the courgettes a few times to get rid of some water, then cover with a small plate and weigh it down with a tin. Leave in the sieve to drain while you prepare the rest of the polpette ingredients.
Drain the lentils and rinse with cold water. Shake dry. Tip into a large bowl and mash as much as you can with a fork or masher.
Peel and finely chop or grate the garlic cloves. Pick the mint leaves and finely shred them. Halve the chilli, flicking out the seeds and white pith for less heat. Finely chop the chilli. Finely grate the lemon zest. Add everything to the lentils along with 1 tbsp tahini.
Squeeze the grated courgettes again to get out any last liquid. Add to the bowl along with the breadcrumbs and some salt and pepper. Mix together to make a stiff mixture. Shape into 12 ping pong ball-sized rounds. These are your polpette.
Line a baking tray with baking paper. Spread the polpette out on the tray. Drizzle with 1 tbsp olive oil. Bake on the top shelf of the oven for 10 mins, then turn them over and bake for another 10 mins.
While the polpette are cooking, trim the remaining courgettes. Use a vegetable peeler to create ribbons. Finely slice the seeded cores and slide the ribbons and cores into a large bowl. Halve the cherry tomatoes and add to the courgettes along with the rocket. Squeeze in the lemon juice, sprinkle in a pinch of salt and pepper and drizzle over 1 tbsp oil. Toss well till everything is dressed.
Arrange the courgette salad on 2 warm plates, top with the polpette and serve.