Peas hull, wash. Peel and finely chop the onion. Peel, wash and chop the potatoes. Heat the fat in a pot. Steam onion in it until transparent. Add potatoes and peas, steam briefly. Deglaze with 1 1/4 l water, bring to the boil. Stir in stock and simmer for about 10 minutes
Peel, wash and slice the carrots. Remove 1/3 of the vegetables from the stock. Puree the rest of the vegetables in the broth. Add the carrots to the soup. Bring everything to the boil and simmer for 5-8 minutes
Cut the sausages into slices. Wash the marjoram, shake dry and remove the leaves. Add the sausages and the rest of the vegetables to the soup and heat it up. Refine with crème fraîche and season to taste. Garnish with parsley if desired.