Defrost the crab meat if necessary. Peel the onion and the ginger.
Dice the onion and chop the ginger or press it through a garlic press. Peel, wash and chop the carrots and potatoes. Sauté the onion and ginger in the hot fat. Add the curry powder and sauté briefly. Season with salt and pepper.
Deglaze with 3/4 l water and bring to the boil, add the stock. Cover and simmer for about 20 minutes. Finely puree the soup. Stir in the crème fraîche, except for 2 tablespoons, and season to taste.
Heat the crab meat in the soup. Serve with the rest of the creme fraiche (put a blob in the middle). Tip: You can also replace half of the carrots with celeriac. Instead of crab meat, you can also use North Sea crab or smoked salmon.