Step 1 Preheat oven to 200°C. Line a large baking tray with baking paper. Place capsicum and onion on tray; drizzle with half of the olive oil. Roast for 20 minutes, or until vegies are tender.
Step 2 Sprinkle both sides of beef fillets with Moroccan seasoning. Heat remaining oil in a medium frying pan set over medium–high heat. Cook beef, turning once, for 2–3 minutes per side, or until done to your liking. Cover to keep warm and set aside.
Step 3 Bring a medium saucepan of water to the boil. Immerse green beans to blanch for 2 minutes, or until bright green and just tender. Drain and refresh beans in a large bowl of cold water; drain again.
Step 4 Meanwhile, place couscous in a heatproof bowl with 1 cup boiling water. Cover bowl; leave to stand for 5 minutes. Fluff couscous with a fork to separate grains.
Step 5 Stir roast capsicum and onion into couscous with green beans and parsley. Serve beef with couscous and half a lemon.