Spread the two slices of bread lightly with the mayonnaise followed by the mustard.
Using a serrated or sharp bread knife, cut the tomato into thin slices and arrange on top of one of the pieces of bread. Season lightly with salt (optional) and pepper to taste. Cover with the turkey and then cover with a mound of the baby salad leaves on top.
Put the other slice of bread on top and cut the sandwich on the diagonal.
