Cut the Hokkaido into approx. 2 x 2 cm cubes. Of course, remove the seeds, you can peel it, but you don`t have to. Wash off well.
Cut the onions into rings. Clean the leek, cut into rings and then rinse well. Quarter the apple and remove the core.
Heat the olive oil in a large saucepan and add the chilli flakes. Fry them briefly until the oil turns a little reddish. Then add onions and leeks and sauté briefly. Add the sugar and let it caramelize a little. Then take it off the stove.
Place the pumpkin and apple pieces in the slow cooker insert, then add the onions and leeks. Then pour the vegetable stock over it, add curry, salt and pepper to taste and stir / fold everything in well. Put the lid on and let it simmer on low for about 7 hours.
At the end of the cooking time, put the soup in a normal saucepan and puree everything with the hand blender. This way the coating of the slow cooker is not damaged. Then stir in the cream and season with salt and pepper.