Heat your oven to 200°C/Fan 180°C/Gas 6. Halve the courgettes and use a teaspoon to scoop out the middles, being careful not to poke through the sides. Arrange the shells on a baking tray and bake for 15 mins.
Finely chop the scooped out courgette middles. Halve the chilli, flicking out the seeds and pith for less heat, and finely chop it. Peel and grate the garlic. Finely slice the spring onion, trimming off the roots.
Pour 1 tbsp oil into a large frying pan and bring to a medium heat. Add the garlic, chilli, spring onion and a good pinch of salt and pepper. Fry for 1 min, then stir in the courgette cores and spinach. Continue to cook, stirring now and then, for 5 mins, or till most of the moisture has evaporated. Stir in the breadcrumbs and crumble in half the pack of feta.
Remove the courgette shells from the oven and spoon in the filling, scattering any extra around the edges. Bake for a further 10-12 mins.
While the courgettes bake, tip the couscous into a heatproof bowl and cover with 300ml boiling water. Pop a plate over the top of the bowl and set aside for 10 mins.
Shred the mint leaves. Zest and juice the lemon. Stir both into the cooked couscous along with a pinch of salt and pepper and 1 tbsp olive oil.
Serve the stuffed courgettes with a good dollop of yogurt, next to a heap of minted couscous.