Preheat the oven to 180°C.
Chop the rosemary leaves.
Peel the squash, remove the seeds and membrane, then cut the flesh into bite-sized pieces.
Arrange them on a baking tray, sprinkle with the rosemary leaves and drizzle with a little olive oil. Bake for about 25-30 minutes until tender.
Meanwhile, cook the lentils in lightly salted water until tender, then drain. This will take about 20 minutes. Shred the ham into small pieces.
Chop the onion and fry in oil until soft, then add the cream and mustard. Simmer until it starts bubbling, then add the ham and lentil. Warm it through. Season with salt and pepper. Finally add the roasted squash and stir through the chopped parsley & seeds.
Serve warm.