Peel and wash the sweet potato and cut into cubes of about 1 cm. Put the lentils in a sieve and rinse thoroughly under cold running water. Peel and finely chop the onion and ginger, peel the garlic as well and press the whole cloves with the flat side of a large knife.
Heat the coconut oil in a large pot. Sauté the onion, garlic, and ginger, stirring, for 3-4 minutes. Add the lentils, sweet potato and spices (curry, turmeric, cumin and chili flakes) and sweat for 1 min.
Pour in the canned tomatoes and about 250 ml of the vegetable stock. Simmer for 25-30 minutes with the lid on and a gentle heat. Stir occasionally and if the lentils need more liquid, add some broth.
Wash the baby spinach and spin dry. Once the lentils are cooked, stir in the baby spinach just briefly until it has collapsed. Season the stew generously with salt and pepper and serve with a dollop of sour cream and chopped cashews.