Brush the aubergine and courgette slices with the oil. Heat the grill on the hottest setting. Cook the vegetables under the grill for 2–3 minutes on each side until lightly cooked.
Arrange the grilled vegetables in a shallow dish. Crumble the feta and sprinkle it over the vegetables.
Whisk all the dressing ingredients together in a small bowl, seasoning to taste with salt and pepper. Pour the dressing over the salad and toss to coat. Scatter with mint leaves to garnish and serve with toasted flat breads or crusty baguette.