In an earlier edition of Daily Halacha, it was noted that if a person places small pieces of bread (less than a Ke’zayit) into a pot of hot soup, the bread is "downgraded" from the Beracha of "Ha’mosi" to the Beracha of "Mezonot." This Halacha is codified by the Shulhan Aruch (Orah Haim 168). The Halachic authorities debate the question of whether this would also apply if one poured soup from its original pot onto small pieces of bread. The question is whether "Irui Keli Rishon" – pouring hot liquid from its original pot onto food – has the effect of Halachically "cooking" the food. If it is considered cooking, then this case is no different from the case of placing small pieces of bread into the original pot, and one would recite "Mezonot" over the bread. If, however, "Irui" is not considered capable of Halachic "cooking," then the pieces of bread in this case are not considered to have undergone cooking, and they retain their status of "Ha’mosi."
In light of this difference of opinion, the Mishna Berura (Rav Yisrael Meir Kagan of Radin, 1839-1933) rules (168:52) that if one eats small pieces of bread upon which hot liquid had been poured from its original pot, he must first wash and recite "Ha’mosi" over proper bread. Otherwise, he puts himself into a situation of uncertainty, as it is unclear whether the proper Beracha over these pieces of bread is "Mezonot" or "Ha’mosi." This is the ruling codified in Yalkut Yosef – Berachot (p. 306; listen to audio recording for precise citation).
Summary: If hot liquid was poured from its original pot onto small pieces of bread (less than a Ke’zayit), it is unclear whether they require "Mezonot" or "Ha’mosi," and therefore one should not eat them unless he first recites "Ha’mosi" over ordinary bread.