Place the roast pieces in a bowl and toss with the flour, salt and pepper until coated. Add the beef to the slow cooker, then add the crushed tomatoes, potatoes, carrots, red and green pepper, onion, paprika, garlic, marjoram, and caraway seed. (Also the fresh parsley if using.)
Pour the beef broth over stew and add the bay leaves.
Set on high for 6 hours or low for 9 hours. Add additional broth if needed.
Last half hour or so remove some liquid to a medium bowl and whisk in the tomato paste. Return that to the crockpot and cook for the last half hour to thicken. Add additional remaining salt if needed.
**If adding sour cream, remove some of the stew broth during the last 5 minutes and slow stir in the sour cream to temper, avoiding curdling and then stir into the slow cooker.
Serve the goulash over egg noodles and garnish with fresh parsley.
