3lbsbeef roast(chuck roast or rump roast or top loin roast)
Rub the beef with salt and pepper all over.
Add water to the Instant Pot. Insert the trivet (the rack that came with the Instant Pot) and put beef on a trivet.
Close the lid and turn the valve to a Sealing position. Press the "Pressure Cook" or "Manual" button and set the time for 20 minutes on High pressure if you like your roast beef "Medium", 30 minutes for "Medium Well" or 40 minutes for "Well Done".
When it's done cooking, let the pressure release naturally completely (until the pin drops, about 20-25 minutes).
Remove the roast beef for the Instant Pot. Slice roast beef against the grain as thinly as possible and serve. (Slicing direction against the grain is very important if you want the texture to approximate deli-sliced roast beef.)