Preheat the oven to 200°C (180°C fan) and put the aubergine and courgette on a baking tray. Drizzle with the olive oil and roast in the oven for 20 minutes.
Add the chickpeas, toss to coat in the olive oil, then roast for a further 10 minutes.
To make the dressing, put the yoghurt, mayonnaise, herbs, capers, olive oil, lemon juice and rind and a big pinch of salt and pepper into a blender and blitz for 1-2 minutes, or until smooth.
Put the lettuce leaves in a large mixing bowl, add the roasted veggies and chickpeas and pour over the dressing. Toss to combine.
Divide between two bowls and top with chopped parsley.