Put the onion, zucchini, red pepper and tomatoes into a shallow roasting tray and season with black pepper. Drizzle with 2 Tbsp of the olive oil and toss to coat. Roast for 30 minutes, stirring halfway through, until vegetables are tender.
Meanwhile, mix together the lemon juice, olive oil and herbs. Season to taste.
Allow the vegetables to cool for 5 minutes, then tip into a bowl with the chickpeas, feta, and the lemon & olive oil dressing. Toss lightly before serving.