Over medium-high heat, heat the pressure-cooker pan and add enough vegetable oil to coat the bottom of the pan. Add enough stew meat to cover the bottom in an even layer without crowding. You'll probably need to work in several batches; if you put too much meat in the pan at once, the meat will steam instead of brown. Brown the meat on all sides, then transfer it to a plate. Continue until you've browned all the meat.