Bring a medium pan of salted water to the boil and add the leeks. Cook for 6-8 mins or until they have a slight bend to them. Drain and set aside.
Heat a large frying pan over a medium-high heat and tip in the quinoa. Toast for 5-6 mins or until lightly browned. Reduce the heat to low and pour in enough water to cover 1cm above the quinoa. Gently simmer for 15 mins, stirring occasionally, until the liquid has been absorbed.
Put the aubergines and leeks directly on the barbecue and brush with oil. Cook for 3-4 mins each side until lightly charred and tender. (Alternatively, brush the aubergines with 1 tbsp oil, put in a really hot griddle pan and cook each side for 3 mins or until lightly charred. Transfer to a plate and set aside. Brush the leeks with 1 tbsp oil and cook on either side for 4-5 mins or until charred. Set aside with the aubergines.) Once cool, cut the leeks in half lengthways.
Combine 3 tbsp of the olive oil with the cider vinegar and half the herbs. Season to taste. Toss the quinoa with the dressing and spoon onto a large plate. Top with the charred aubergines and leeks, and sprinkle over the tomatoes, hazelnuts and cheese. Finish with the reserved herbs and a good glug of the remaining olive oil.