Set Instant Pot to saute mode and add oil. Sear roast on each side for 2-3 minutes, until lightly browned.
Add peppers to Instant Pot; use a wooden spoon to scrape up brown bits from bottom of the pot. Add gravy mix, ranch mix, and butter to the Instant Pot.
Seal the lid and set IP on the manual setting to cook on high pressure, 75 minutes. Once cook cycle is up, allow pressure to naturally release for 10-15 minutes before releasing remaining pressure.
Notes
This roast makes a wonderful freezer meal! Simply put all of the ingredients from the ingredient list above in a freezer bag. When ready to serve, put the contents of the freezer meal and 1 cup of water in your Instant Pot and cook as directed.
This can be converted to a slow cooker meal. Add roast ingredients to a slow cooker and set on low for 6-8 hours to have one of the best roasts you'll ever eat.
I prefer this roast with mashed potatoes, but you can also serve with rice, mashed cauliflower, or egg noodles.