Heat the oil in a frying pan and gently fry the onion and courgette for 4–5 minutes, stirring regularly, until softened and beginning to brown.
Add the chickpeas, harissa and tomatoes and cook for 3–4 minutes, stirring occassionally, until the tomatoes are softened but still holding their shape. Add a splash of water if the mixture begins to stick.
Add a squeeze of lemon juice and season with salt and pepper.
Spoon the yoghurt onto two plates or shallow bowls, top with the warm chickpeas and sprinkle with the herbs. Serve immediately.