Except we should go and buy food (ei mhti poreuqente hmei agoraswmen brwmata). This is a condition of the third class with the aorist subjunctive (agoraswmen), where the conjunction is usually ean (with negative ean mh), but not always or necessarily so especially in the Koin. So in 1 Corinthians 14:5ei mh diermhneuh and in Philippians 3:12ei kai katalabw. "Unless" is better here than "except." Food (brwmata), means eaten pieces from bibrwskw, to eat, somewhat like our "edibles" or vernacular "eats."