What was found
DURING TAXI OUT AT LAS PAX AND FA COMPLAINED OF STRONG FUEL ODOR IN THE CABIN AND REPORTED SEEING A HAZE. RETURNED TO GATE. PERFORMED ENG RUNS PACKS ON APU ON GENS ONLINE INSPECTED VENTRAL STAIR AREA, WHEEL WELL AREA, CABIN CHECKED FOR FUMES AND ODOR. COULD NOT DUPLICATE. CHECKED A/C FOR FUEL LEAKS, INSP APU SHROUD AREA, NO LEAKS NOTED.