Beef goulash soup

Name: Beef goulash soup
Ingredients: 1 tbsp rapeseed oil; 1 large onion, halved and sliced; 3 garlic cloves, sliced; 200g extra lean stewing beef, finely diced; 1 tsp caraway seeds; 2 tsp smoked paprika; 400g can chopped tomatoes; 600ml beef stock; 1 medium sweet potato, peeled and diced; 1 green pepper, deseeded and diced; 150g pot natural bio yogurt; good handful parsley, chopped