For the Instant Pot, set your pot to sauté and sear the roast on both sides in olive oil.
Place onion chunks under the roast in the pot. Add in all of the packages followed by the water.
Close the lid and seal, and make sure that the value is set on SEALING.
Use the manual button and then set for 2 hours.
Let it release naturally (about 24-26 minutes)
Remove and serve in the bucket of gravy. For thicker gravy add a blended mixture of flour and water at the ratio of 1 to 4. When adding to pot stir constantly to avoid lumps.