Remove the seeds from the pumpkin. Cut the pumpkin into slices and peel. Mix oil, syrup and vinegar and mix with the pumpkin. Line a baking tray with baking paper. Spread the pumpkin on it.
Peel, wash and halve the potatoes. Also spread them on the tray. Season everything with salt and pepper. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for about 15 minutes.
Wash the chives, dab dry, cut into fine rings, put some aside for garnishing. Mix yoghurt with the remaining chives, season with salt and pepper. Clean and wash spring onions and cut them into fine rings.
Sprinkle pumpkin seeds over the pumpkin slices. Bake at the same temperature for another 5-10 minutes. Serve pumpkin and potatoes with herb yoghurt. Sprinkle with chives and spring onions.