Lechem Mishna: A Broken Challa/Matza

If a square matzo has its corners broken can you use it for lechem mishna?

Shalom!

Thank you for your question!

As you know, any time one begins a meal on Shabbat, the blessing on bread must be recited while holding two loaves, a mitzva referred to "Lechem Mishna" – a double portion.

We do this to recall that a double portion of Manna was given to the Jewish people every Friday so that they would have food for Shabbat. Manna would not fall on Shabbat as “gathering” is one of the forbidden Shabbat labors. It is worth mentioning that although every meal must begin with two loaves, there is no obligation to eat form both loaves. It suffices to eat from only one.

It is rather important that the loaves are completely whole. However, especially when it comes to matza, it is very difficult to ensure that bread/matza is completely whole with nothing lacking whatsoever. Both women and men are equally obligated in the Lechem Mishna requirement,

As a general rule, a subjective glance will be enough. If it appears to the eye as whole then one can consider it whole even if some crust has broken off somewhere but if it appears broken to the eye it should be treated as such.

In an emergency where two whole loaves are simply not available, one can combine any two pieces of bread. So too, sometimes a broken loaf can be made to look whole by reattached it by means of a toothpick or the like. One may also use one whole bread and one whole matza for the lechem Mishna requirement (but not on Passover, of course!). Some people even recite the “mezonos” blessing on two pieces of cake or on two cookies when eating such items on Shabbat after kidush shabbos morning though this practice is not too widespread.

Shabbat 117b; Ramabm, Hilchot Shabbat 30:9; OC 274 and commentaries; OC 168:2; Kitzur Shulchan Aruch 77:17