Add Beef Rump Roast (3 pound), Pepperoncini Pepper (1 jar), Dry Italian Salad Dressing Mix (1 package), Brown Gravy Mix (1 package), and Water (3/4 cup) to the Instant Pot.
Close and lock lid. Cook on Manual High Pressure for 60 minutes, then natural release pressure.
Rest for 5 minutes. Shred big chunks of beef to allow juice and peppers to mix in with the meat.
Serve alone, with side dishes, on a sandwich or any way you want!