Which Kind of Cooked Food Items May be Used for the Erub Tabshilin?

The Shulhan Aruch (Orah Haim 527) writes that the cooked food used for the Erub Tabshilin must be a food item that is "Ra’ui Le’lafet Bo Et Ha’pat" – meaning, it is commonly eaten together with bread. Thus, it is customary nowadays to use a boiled egg, as people commonly eat egg with bread in a sandwich.

If a person does not have an egg, he should not use for the Erub something like rice, which is not normally eaten together with bread. Instead, he should use either a cooked piece of meat, a can of cooked tomatoes, or even a can of sardines, as these foods are commonly eaten together with bread.