Using a large cast iron pot, over medium heat, add bacon pieces and cook until crispy. Reserve fat.
Add onions and if there isn't enough bacon fat, add 1 tablespoon of butter. Sauté the onions for 3-4 minutes until tender. Stir in garlic, and sauté for about 30 seconds. Then add the remaining vegetables, potatoes, carrots, parsnips, and celery. Pour in the vegetable stock, season with salt and pepper. Bring to a boil, then reduce heat and cook until vegetables are tender, about 20-30 minutes.
Roux: Melt butter in a skillet over low-medium heat, add flour and combine, then remove from heat and stir in paprika. Add a couple of ladles of soup and mix into the roux.
Bring soup to a boil and stir in the roux into the soup. Soup should be slightly creamy. Stir in parsley. Garnish with sour cream, parsley and crispy bacon. Serve with crusty bread.
