On the saute setting, drizzle olive oil over the bottom of the pot and sear each side of the roast. I like to cut mine up into about softball sizes. This allows you to add more flavor with searing more sides, but it also enables the pressure cooker to cook the roast quicker. Also, season each side of the roast with salt and pepper before you sear the sides.
Remove the roast parts and drizzle more olive oil in the bottom of the pot, add in the chopped onion and saute until the pieces begin to brown. Add in the garlic and saute for another minute or so.
Add back in the roast with the onion and garlic, turn off the saute setting and add in the cooking red wine as well as the beef broth.
Now, place the steam basket over the roast. Toss the potatoes with olive oil, salt, and pepper and then pour into the steam basket. Set the Instapot on high for 75-90 minutes. If the roast is less than 5lb, set it closer to 75min.
Once the pressure cooker is finished, allow the pressure to release naturally. You can take this time to make a gravy if you'd like. Once the pressure cooker is finished releasing the pressure, take the lid off and remove the steamer basket. The potatoes will be perfectly steamed. Set the basket aside.
Take the roast out, hopefully the beef with be so fork tender it will be falling apart. Plate the roast and add the potatoes around the sides. Spoon the onions and garlic over the top of the roast and potatoes.
I also love having carrots with pot roast, but I like to roast them in the oven instead of steaming them in the pressure cooker. Not only will they not fit very well in my instapot, but I also love the flavors roasted potatoes give. If you'd like roasted carrots, toss them with olive oil, salt, and pepper and spread them out on a baking sheet. Bake at a 400°F oven for 20-30 minutes. Serve immediately with the roast and potatoes when finished roasting.