Pop the pumpkin on a baking tray. Drizzle with oil and season well with salt and pepper. Stick in a slow oven until the pumpkin is tender when a fork is inserted. In a large pan, fry up the onion and curry paste in the butter until onion is well cooked and curry is beautifully fragrant. Pop in pumpkin, lentils and stock. Cover and simmer until lentils are cooked and pumpkin has broken down. If you are in a hurry to get it on the table, use the zoomy stick and serve. If time is on your side though, Add some extra fluid and allow to continue gently simmering away for as long as possible and zoom up just before serving.