Toss the courgettes with 1 tbsp oil, and cook in batches on a very hot griddle pan for 3-4 mins each side, until well coloured but al dente. Put in a bowl and season.
Mix 1 tbsp of oil with the lemon juice, mint and chilli. Toss through the courgettes. Cover and marinate for 30 mins.
Meanwhile, combine the ricotta, dill and lemon zest, and season with salt. Put the courgettes in a serving dish and dot with the ricotta mixture. Scatter over the pine nuts, mint leaves, rocket and extra chilli flakes, and drizzle with the remaining oil.