Peel and dice the sweet potatoes. Put the potatoes in a large pan with a pinch of salt. Pour in water until the potatoes are submerged. Bring to the boil, drain when tender (about 15-20 minutes).
Sauté the onion and garlic until translucent in a large frying pan with some oil, then add the pepper and fry this along.
Briefly fry the spinach with the onion and pepper until the spinach shrinks. Season with the cumin, paprika and salt and pepper to taste. Mix well.
Mash the sweet potato creamy with a potato masher and add the butter and sour cream while mashing.
Now add the spinach mixture to the mash and add the sun-dried tomatoes, feta and walnuts. Mix well.
Serve the mashed potatoes with a nice salad on the side and enjoy!