Bring a large pot of salted water to a boil. Add cabbage leaves. Cook until tender. About 4 minutes. Drain and cool, slice off the thick rib on each leaf.
In a saucepan over medium heat combine tomatoes, broth, salt, bay leaf, brown sugar, garlic and thyme. Add pepper to taste.
Bring to a boil and reduce heat and simmer 20 minutes, breaking up tomatoes while cooking.
In a large bowl combine beef, veal, kielbasa, rice, sour cream, parsley and salt.
Melt butter in a large skillet over medium heat, add onion and saute for about 3 minutes, until onion is tender. Add garlic and saute another 2 minutes. Add paprika and allspice and cook another minute. Until fragrant.
Combine beef and onion mixture and add pepper to taste.
Place about 1/2 cup beef mixture onto each leaf and roll up, folding ends over as you roll. Place seam side down into a 9x13 glass casserole dish.
Pour sauce over cabbage rolls and cover tightly with foil.
Bake for 1 hour. Remove foil and bake another 30 minutes or until cabbages are lightly browned.