Spread the tortilla with the mayonnaise, leaving a ½-in. (15-mm) border around the outside unspread. (For a richer, moister sandwich, double the quantity of mayonnaise.)
Arrange the lettuce leaves in the center of the tortilla, leaving a border of about 2in. (5cm) uncovered.
Arrange the tomato, bacon, and turkey on top of the lettuce.
To roll the wrap, first fold the uncovered rim of the tortilla on opposite edges of the circle toward the center. This closes the ends of the roll to hold in the filling. Then roll the tortilla tightly. The mayonnaise on the edge of the tortilla helps seal it closed.