Step 1 Preheat oven to 180°C. Line a large baking tray with baking paper. Place chopped pumpkin and capsicum on prepared tray; spray with olive oil, sprinkle with za’atar and toss to coat. Transfer tray to oven and roast vegetables for 25 minutes, adding zucchini to tray for last 10 minutes.
Step 2 Meanwhile, heat olive oil in a large saucepan set over medium heat. Add onion to pan and cook, stirring, for 5 minutes, or until soft. Add garlic and cook, stirring, for 1 minute, or until fragrant.
Step 3 Add lentils to saucepan; cook, stirring, for 1 minute. Combine stock powder with 1 cup boiling water in a small heatproof bowl. Stir hot stock and couscous into lentil mixture. Cover pan, remove from heat and leave to steam for 3 minutes. Fluff cooked couscous with a fork to separate grains.
Step 4 Add roast vegetables and half of the parsley to saucepan; stir and season with black pepper.
Step 5 Divide pilaf among 4 plates; garnish with remaining parsley.Top each dish with a dollop of Greek-style yoghurt and serve.