Step 1 Preheat oven to 175°C. Spray a large, deep flameproof casserole dish with olive oil and set over medium heat on the stovetop. Add lamb; cook for 3–4 minutes, or until browned on all sides.
Step 2 Add half of the olive oil to dish with onion wedges; cook, stirring, for 2 more minutes, or until soft. Add cumin, chickpeas, tomatoes, spinach, lemon juice and lemon zest; stir to combine and bring to the boil. Cover dish and place in oven to cook for 40 minutes.
Step 3 Place remaining olive oil and couscous in a medium bowl with 3 cups boiling water; stir, cover bowl with cling film and leave to stand for 5 minutes.
Step 4 Fluff couscous with a fork and divide among serving bowls. Top couscous with lamb, garnish with chopped parsley and serve.