Place Pork, Onions, Tarragon, Salt, Pepper, Caraway, Bell Pepper And Tomato In A Stock Pot. Add Stock. Bring To A Simmer For 30 Minutes. Add Lentils, Simmer For 30 Minutes. Saute Flour In Oil Until Browned, Add Sugar, Garlic, Parsley, Celery And Paprika. Saute For 3 Minutes. Add To Soup, Along With Wine And Mustard Powder. Bring To A Boil. Add Vinegar. Boil 1 Minute. Remove From Heat, Stir In Sour Cream And Serve.