Preheat the oven to 190°C.
Cut the squash in half, scrape out the seeds, then cut them into slices and remove the skin.
Place the squash pieces on a baking tray, rub them with 2Tbsp of oil and bake in a hot oven until tender (for about 45 minutes).
Peel the onion, cut in half then slice and mix with the remaining oil. After 25 minutes of baking add the onion to the squash. Stir through after 15 minutes.
Meanwhile, cook the lentils according the packaging instruction and drain (they should be al dente). Add the dressing and toss.
Transfer the roasted squash and onion into a large serving dish and season with salt and pepper.
Add the harissa lentils, taste and adjust the seasoning to your liking.
Fold through the green leaves and serve.