Heat the oil in a medium saucepan. Add spring onions, garlic and cumin and heat for about 1 minute. Add the broth and bring to a boil. Take the pot off the fire, mix in the couscous and let stand for about 10 minutes to soak until the liquid is completely absorbed.
Put the couscous in a bowl, add the tomatoes, chilli, lemon juice, parsley and mint. Season with pepper and salt and let it steep for at least an hour so that the ingredients can develop their full aroma.
Just before serving, line a bowl with lettuce leaves, add the couscous and sprinkle with the pine nuts.