Potatoes sour soup

1 kg potatoes, cubed
250 g soup vegetables  (onions, carrots, peppers, parsnips, celery, etc.), chopped
2 tomatoes, finely chopped
1 teaspoon paprika powder
lemon juice, to taste (optional)
lovage/parsley
2 tablespoon olive oil
salt

Cook the potatoes along with the onion, in water enough to cover them.

When the potatoes are half cooked add the other vegetables. Cook for 5 minutes than add the tomatoes.

When the tomatoes have softened add the lemon juice and some water, paprika powder and salt to taste.

Garnish with fresh lovage/parsley and olive oil.