What was found
F/A REPORTED FUMES AND ODOR OF BURNING FOOD THROUGHOUT CABIN BUT HEAVIER IN MID CABIN AREA. CREW UNABLE TO ISOLATE, RETURNED TO DEPARTURE. PERFORMED SMOKE OR FUMES IN CABIN CONDITIONAL INSPECTION IAW AMM 05-51-56 AND TASK 21-00-21. INSPECTED BOTH LT & RT. ACFT PACK BAYS NO CONTIMANATION FOUND. RAN BOTH ENGINES AND APU NO ABNORMAL ODORS NOTED. RAN ALL GALLEY OVENS, IFE, COFFEEMAKERS, CHILLERS, BUN WARMERS, AND ALL CABIN LIGHTS. LOOKED UNDERNEATH ALL CABIN SEATS ON ENTIRE ACFT FOR ABNORMAL ODOR OR HEAT NOTHING FOUND. INSPECTED BOTH ENGINE INLETS AND PACK BAY INLETS FOR POSSIBLE DEBRIS NOTHING FOUND.