Preheat oven to 200°c. Place pumpkin and onion on an oven tray and drizzle with 11/2 tbs oil. Season with salt and pepper. Roast for about 35-40 minutes or until golden.
Meanwhile, place lentils in a saucepan with garlic and 4 cups cold water. Bring to the boil, then reduce heat to a simmer and cook for 15-20 minutes or until lentils are just tender. Drain and discard garlic. Cool for 15 minutes.
Meanwhile, to make yoghurt dressing. Whisk yoghurt, cumin, garlic and lime juice together to combine. Add herbs and season to taste with sea salt flakes and cracked black pepper. Add 1-2 tbs water to thin, if necessary.
Toss lentils with remaining olive oil, lemon juice and lemon rind. Add rocket and spinach leaves and toss through the pumpkin and onion. Season to taste. Place on a serving platter and drizzle with dressing, to serve.