German Potato Soup (Kartoffelsuppe) with Sausage

Heat olive oil in a large pot or Dutch oven over medium heat. Add the diced onion and leek and cook until softened, about 5 minutes.

Add the sliced sausage to the pot and cook until lightly browned, about 5 minutes.

Add the diced potatoes, carrots, and celery to the pot. Cook for another 5 minutes, stirring occasionally.

Pour in the chicken broth, add the bay leaf, marjoram, and thyme. Bring to a boil, then reduce heat and simmer for 20-25 minutes, or until the potatoes are tender.

Remove the bay leaf and season with salt and pepper to taste.

Ladle the soup into bowls and garnish with fresh parsley and a dollop of sour cream, if desired. Serve hot.