The fastest way to perform the Qadha prayers is to recite the obligatory parts of Salah only with out any recommended part. Starting the Qadha prayer with intention in the heart only and no Azaan and no Iqamah but only Takbiratul Ehram then reciting Sura Al-Hamd and short Sura, then Rokoo' with Subhana Rabbial Adheem, then Sojood with Subhana Rabbial A'la.
Wassalam.