1Let cracker breads come to room temperature as directed on package. Meanwhile, mix cream cheese, blue cheese, milk, bacon, chives and pepper.
2Spread half of cream cheese mixture evenly over 1 cracker bread. Layer half of roast beef, salad greens and tomatoes (in that order) on cracker bread, leaving 4 inches at one side covered only with cream cheese mixture. Beginning at side covered with fillings, roll up tightly. Repeat with remaining cracker bread, cream cheese mixture and fillings.
3For uniform-size slices, cut ends without fillings from each roll (about 1 inch from each end). Cut remaining portion of each roll into 5 slices. Serve immediately, or wrap securely with plastic wrap and refrigerate no longer than 24 hours.