Heat oil in frying pan and fry onion until transparent. Add the paprika and flour and stir inches Cook for about 1 minute. Add the tomatoes, stoc, thyme, and season to taste with salt and pepper. Cut sausages to lengths of about 1 inch, add to mixture in frying pan, and cook for 15 minutes before adding green pepper. Cook for further 15 minutes. Serve with potatoes or rice and seasonal vegetables.