Add sliced and halved or quartered kielbasa sausage to a non-stick skillet. Cook over medium-high heat, until browned in spots. Remove to a bowl and set aside.
In a large soup pot, heat oil over medium heat. Add the onion, celery and carrots to the pot and cook, stirring, until softened, about 4-5 minutes. Add flour to the pot, if using and cook stirring, about 30 seconds. Add chicken broth, tomatoes, 1/2 of the chopped parsley, sweet and. smoked paprika and bay leaf to the pot and stir to combine. Bring to a boil, then reduce heat slightly and simmer 10 minutes.
Using a potato masher, smash the tomatoes to break up. Add the rinsed kidney beans and stir in. Simmer 10 minutes more. Remove bay leaf and discard. Add kielbasa sausage and the remaining chopped parsley. Stir in and allow to cook a few minutes to warm through.
Taste soup and add salt and freshly ground pepper, as needed. If soup tastes "flat" at all, it needs more salt.
Serve warm, garnished with more freshly chopped parsley and a dollop of sour cream on top, if you like.
Notes
1. A bit of flour is added to give a tiny bit of thickness to the broth. If you'd prefer to omit for a gluten-free soup, you can do so.2. If you don't have fresh tomatoes on hand, you can use a couple of whole, canned tomatoes instead.3. If you don't have smoked paprika, add an extra 1 tsp of sweet paprika.Be sure to read the notes above the Recipe Card for more tips on making this recipe. You will also find step-by-step photos there, as well, for a visual summary of the steps to make this soup.