823. A Mixture that Includes Chometz
116:18 If possible, one should perform hagalah in the presence of a Torah scholar who is knowledgeable in the laws of the process.
117:1 If one finds a mixture that includes chometz on erev Pesach before nightfall, it is the same as other forbidden food that is nullified if the forbidden thing is less than one part in 60. Therefore, if one finds a kernel of grain in a chicken or in a cooked dish, he simply throws it away and the rest is permitted to eat, even on Pesach (so long as it has cooled off before Pesach begins - Mishnah Brurah 447:19). During Pesach, however, chometz is forbidden even in the smallest amount, even for benefit. If one finds a kernel of grain from one of the five species, or the smallest amount of chometz, he must ask a Torah scholar how to proceed. (If one will incur a great loss, he may sell the mixture to a non-Jew, minus the value of the chometz it contains - MB 447:3.)