Romanian ciorba de perisoare (sour meatball soup) with sauerkraut

Ingredients

• 1 tablespoon olive oil
• 1 onion, finely diced
• 2 carrots, peeled and grated
• 2 stalks celery, finely chopped
• 1 medium parsnip, peeled and finely chopped
• 1 litre salt-reduced chicken stock*
• 3 tablespoons tomato paste
• 2-3 tablespoons red wine vinegar
• 500 millilitres water
• sour cream and sauerkraut, to serve
• 1/4 cup chopped parsley
• Meatballs
• 250 grams beef mince
• 250 grams pork mince
• 3 tablespoons uncooked rice
• 1 egg, beaten
• 1 teaspoon paprika