Hataras nedarim. If the challah got mixed up with the dough from which it was separated and the volume of the dough is not 101 times that of the challah, one can do hataras nedarim in front of three men. The dough then reverts to tevel and another piece of challah should be separated (רמ"א שכ"ג ס"א ) with a bracha (שו"ת חת"ס יו"ד סי' ש"כ ).
L’chatchila, the hatara should be done the same way it is for a neder. Therefore, one should state, “I regret having made this piece challah. Had I known I was going to regret it, I would not have done it” (חכמת אדם דיני חלה ). The three then declare, “מותר לך ” three times.
Since generally the wife does the hafrasha, while the dough belongs to the husband, the husband should do hataras nedarim on behalf of himself and his wife.
If some of the dough was already eaten, in Eretz Yisroel, hataras nedarim can no longer be done, because that would retroactively make what was eaten tevel (ש"ך סק"ו ). Outside Eretz Yisroel, where it is permissible to eat and then set aside challah, one can do hataras nedarim as long as there is some dough or bread left.
