Polish Zurek: Sour Rye Soup with White Sausage, Potatoes and Soft-Boiled Egg

If making zakwas from scratch, stir 1/2 cup rye flour with 2 cups warm water, 2 crushed garlic cloves and a bay leaf in a jar, cover loosely with cloth and leave at room temperature for 4 to 5 days until pleasantly sour. Shortcut: buy a bottle of zurek starter from a Polish deli.

Serves 6

Ingredients

• 1 1/2 cups zakwas (fermented rye starter, store-bought or homemade from rye flour and water)
• 6 cups chicken or vegetable stock
• 1 pound fresh Polish white sausage (biala kielbasa) or mild fresh pork sausage
• 4 ounces smoked bacon, diced
• 1 large onion, finely chopped
• 4 garlic cloves, minced
• 1 pound potatoes, peeled and cut into 2cm chunks
• 2 bay leaves
• 6 allspice berries
• 1 tablespoon dried marjoram
• 2 tablespoons prepared horseradish
• 1/2 cup heavy cream or sour cream
• 6 eggs, soft- or hard-boiled and halved
• Salt and black pepper, to taste

Instructions

1. If making zakwas from scratch, stir 1/2 cup rye flour with 2 cups warm water, 2 crushed garlic cloves and a bay leaf in a jar, cover loosely with cloth and leave at room temperature for 4 to 5 days until pleasantly sour. Shortcut: buy a bottle of zurek starter from a Polish deli.
2. Place the white sausage in a pot with the stock, bay leaves and allspice. Bring to a gentle simmer and cook for 15 minutes, then lift out the sausage, slice it into coins and set aside. Keep the stock.
3. In a large soup pot, cook the bacon over medium heat until the fat renders and the pieces are golden. Add the onion and cook until soft, about 6 minutes, then stir in the garlic and marjoram for 1 minute.
4. Add the potatoes and the reserved sausage stock. Simmer for 15 minutes until the potatoes are just tender.
5. Shake the zakwas jar well, then pour it into the soup through a sieve. Stir and simmer gently for 5 minutes. Taste: it should be bright and tangy. Add more zakwas for sharper sourness.
6. Stir in the horseradish and the cream, then return the sliced sausage to the pot. Warm through without boiling. Season generously with salt and pepper.
7. Ladle into deep bowls and nestle a halved boiled egg into each. Finish with a pinch of extra marjoram and serve with dark rye bread.
8. Zurek is one of Poland's oldest soups, built on the same fermented rye base that farmhouses once kept bubbling in a corner of the kitchen through the cold months. Its sour tang, smoky sausage and warming marjoram make it the classic Easter breakfast, but Poles eat it all through autumn and winter, sometimes served inside a hollowed round loaf of bread. As the days shorten and root cellars fill with potatoes, a steaming bowl of zurek is comfort food with centuries of history in every spoonful.

Nutrition (estimated, per serving)

• Calories: 480 kcal
• Protein: 24g
• Fat: 31g
• Carbohydrates: 26g
• Fiber: 3g
• Sugar: 3g
• Sodium: 1150mg