Boil the chicken breast, let it cool, and shred it along the grain.
Wash and prepare vegetables such as lettuce, tomato, and cucumber.
Cut whole wheat or rye bread in half.
Spread mustard or mayonnaise sauce on the bread.
Place chicken breast, tomato, cucumber, and lettuce on the bread.
Cover with the other slice of bread to make the sandwich.
Cut into bite-sized pieces.