Place the trivet inside of the inner pot, and pour broth in to pressure cooker pot, add roast and top with dressing, seasonings and stick of butter.
Place lid on and cook on high pressure for 90 minutes. Reduce the cook time if roast is thawed, for around 45-50 minutes.
Naturally release the pressure.
Remove meat, and place on to platter or serving dish.
If making gravy:
In a small bowl, mix together cold water and flour. Stir until there are no lumps.
Leave juices in the pot and turn the "saute" setting on.
Once meat juices are heated through and almost boiling (don't forget to stir so it doesn't burn) slowly add in and stir in the flour and water mixture.
Stir and cook until juices thicken to a gravy. If it does not thicken to a gravy after a couple of minutes, try adding more of a flour mixture. You could have more juices than I did.
Video
Notes
You can also make this recipe if you do not have a frozen roast. If your roast is thawed, cook for only 45-50 minutes instead!