Peel the potatoes, wash and peel the pumpkin (unless you are using Hokkaido pumpkin which does not need to be peeled), and remove the seeds and fibers.
Cut the potatoes and pumpkin into 2-cm dice and put to one side.
Heat up a saucepan and briefly toast the coriander, fennel, cumin and mustard seeds in it. Remove the seeds from the pan and pound in a mortar.
Peel and halve the onion and add into mixing bowl. Chop for 8 seconds / speed 5.
Use the spatula to scrape down. Add the butter and remove the measuring cup, sauté for 4 minutes / 230°F|110 °C.
Add the crushed spices and sauté again for 2 minutes / 230°F|110 °C.
Add the diced potato, turmeric, coconut milk and 1 tsp of salt and cook everything for 5 minutes / 212°F|100 °C / speed 1 / stir.
Then add the diced pumpkin and cook for 15 minutes / 212°F|100 °C / speed 1 / stir.
If the pumpkin is not yet cooked after the cooking time has elapsed, continue to cook for 2 more minutes.
Before serving, season the curry with salt to taste and sprinkle with the coriander leaves. Enjoy!