Clean the Brussels sprouts, separate the outer dark green leaves one by one and set them aside for the insert. Peel and roughly dice the potatoes. Cook the inside of the Brussels sprouts and the potatoes in the broth for approx. 20 minutes, then puree them finely. Season with salt, pepper and a little nutmeg, stir in the creme fraiche.
While the soup is boiling, blanch the outer leaves of the Brussels sprouts in boiling salted water, then rinse with ice water. Halve the onion and cut into rings, sauté in the butter. Roast the pine nuts and roughly chop them. Dice the ham and add to the onions. Add the Brussels sprouts leaves to the onions and fry them for approx. 5 minutes, the leaves can turn a little brown. Finally stir in the pine nuts. Arrange the insert on the soup.