Clean, wash and cut the spring onions into rings. Clean chanterelles and cut them into smaller pieces if necessary. Peel, wash and cut the potatoes into pieces.
Heat 2 tablespoons of fat in a large pot. Fry the chanterelles for about 5 minutes, turning them over. Fry the spring onions briefly. Season with salt and pepper. Take out.
Heat 1 tablespoon of fat in the pot. Sauté the potatoes in it. Add 1 1/4 l water and broth, bring to the boil. Simmer covered for about 20 minutes.
Whip the cream lightly. Mash the potatoes in the broth briefly with a hand blender. Stir in half the cream. Season to taste with salt and pepper.
Re-heat chanterelles and spring onions in the soup. Serve with 1 dollop of cream and possibly borage flowers.