While the gnocchi is cooking, add the garlic, capers and chilli flakes (if using) to the courgettes and sizzle for 1 minute until starting to crisp. Add the lemon juice and stir, scraping any bits off the bottom of the pan. Add the butter and sizzle for 30 seconds until it smells nutty. Toss in the cooked gnocchi and enough of the reserved cooking water to create a glossy sauce that coats the gnocchi. Stir in most of the basil and leave to wilt for a few seconds, then divide between warmed bowls. Serve topped with the remaining basil and a fine grating of cheese.