In the court case in the United States of
White City Shopping Ctr., LP v. PR Rests., LLC, 21 Mass. L. Rep. 565 (2006), the judge ruled that a true sandwich (from a legal perspective) must include at least
two slices of bread.
[25] Many open-faced sandwiches do not satisfy this condition, although some served in diners and restaurants in the northeastern U. S. actually do pile the meat and gravy atop two overlapping slices of bread.