Brad Pitt's got one hell of an appetite ... for burgers and more friendly hangouts with gal pal Alia Shawkat. The "Once Upon a Time in Hollywood" star and Ali were spotted at In-N-Out in L.A. the day after they both also hit up a Thundercat show at The Wiltern. Brad, seen wearing the same hat he wore at the concert, used to be one party animal -- no word if he went animal style at the burger joint.