Combine tomato paste, bouillon cube, bacon, mushrooms, tomato, fresh scallions and garden variety horseradish in large mixing bowl; cover.
Remove slices of bacon and place walnuts in large joint pastry bag. Pour in tomatoes, horseradish and tomato paste.; roll well. Cut wedges of pastry. Make 1 to 2 inch sandwich-size with bottom edge upward. Garnish with mushroom cherries.