Heat the oil in a large frying pan, add the aubergine and stir well. Cook over a high heat for 5 minutes, continuing to stir until lightly browned. Reduce the heat to medium and add the tomatoes and the lamb. Cover and cook for a further 4-5 minutes.
Meanwhile, heat the rice according to pack instructions. In a bowl, mix the yogurt with the harissa to create a ripple effect. Heat a griddle pan, add the halloumi and cook for 1-2 minutes on each side, until charred.
Stir the rice into the hot aubergine and lamb mixture. Add the orange zest and juice, rocket and herbs, then stir well. Spoon onto plates, top with the grilled halloumi and dollop with the harissa yogurt. Serve with warm pitta bread.