Step 1 Combine lemon zest, parsley and chives in a small bowl. Line a steamer with baking paper; set over a large saucepan of gently simmering water. Place fish fillets in steamer and sprinkle evenly with herb mixture. Cover steamer and cook fish for 8 minutes, or until cooked through.
Step 2 Meanwhile, heat olive oil in a large non-stick frying pan or wok set over medium–high heat. Add sliced onion and cook, stirring, for 3–4 minutes, or until soft.
Step 3 Add garlic, asparagus and sugar snap peas to pan (or wok); cook, stirring, for 2–3 minutes, or until greens are almost tender. Add grape tomatoes and cook, stirring, for 2 minutes, or until almost wilted. Add kale and cook for 1 minute, or until wilted.
Step 4 Cook couscous according to packet instructions and cover.
Step 5 Serve lemon and herb fish with vegetables, 1/2 cup cooked couscous and lemon wedges.