1) Arrange the courgette slices in a single overlapping layer on a platter. Dust with salt and pepper, then drizzle with a three-count of olive oil and the lemon juice.
2) Put the courgette into the refrigerator for about 10 minutes to give the flavours a chance to penetrate. Remove from the refrigerator, scatter with leeks then sprinkle with the herbs.
Garnish with the ricotta cheese and mint leaves, if using. Serve.