Combine cauliflower and stock in a medium saucepan. Bring to a boil; cook 10 minutes or until tender. Place cauliflower mixture in a blender. Add milk, butter, 1/4 teaspoon pepper, salt, and cheese. Remove center piece of blender lid (to allow steam to escape); secure blender lid on blender. Place a clean towel over opening in blender lid; process until smooth.
Place bread on a baking sheet. Broil 2 minutes or until toasted on one side.
Cook bacon in a large ovenproof skillet over medium-high heat until crisp. Remove bacon with a slotted spoon. Sprinkle turkey with remaining 1/4 teaspoon pepper. Add turkey to pan; cook 2 minutes on each side or until done. Remove turkey from pan; let stand 5 minutes. Shred turkey into large pieces. Arrange bread slices in a single layer, toasted side down, in pan. Top bread slices evenly with turkey. Pour cauliflower mixture evenly over turkey; broil 3 minutes or until sauce begins to bubble. Top each serving with 1 tomato slice, one-fourth of the bacon, and herbs.