Situation You baked challa with chicken, both uncovered, in the same oven (the chicken DID have sauce).
Status The challa becomes non-kosher even if the sauce was dry by the end of cooking.
Reason A rabbinic enactment requires that challa be pareve, lest someone eat it with the opposite gender food.  Consult a rabbi for exceptions. 
Note The rabbinic enactment applies to all bread, unless it looks different from normal bread or is small enough to eat at one meal.