Peel the potatoes and onion and cut into small cubes. Sauté the pieces in a pot with oil and butter.
When the onions are translucent, deglaze with the soup. Cook until the potatoes are soft, then add whipped cream and cook for another 5 minutes.
Puree with a hand blender or stand mixer, slowly blending in the wild garlic leaves.
Season to taste with salt and pepper.