Toss brinjal and courgettes in the salt and stand for one hour before rinsing and draining. ("degorging
" the brinjal is optional)
Dry in a clean cloth. Toss tomatoes, brinjal, courgettes, peppers and onions in olive oil and put on a baking sheet. Scatter with garlic and basil. Roast for 20 minutes. Cool.
Cook couscous in chicken stock according to instructions. Cool.
DRESSING: Whisk together harissa paste, water, olive oil and lemon juice. Put couscous in a large wide salad bowl. Layer vegetables, cheese and olives. Top with salad leaves, coriander and spring onions. Just before serving, drizzle a little dressing over top and serve remainder in a jug to be added according to taste.