What temperature & for how long should a Pot Roast be cooked?

with using chuck steak the slower the better. cook meat (you can add onions and celery) for 1 and half of 180-190 degrees (Less if fanforced oven-temp around 170degrees) and last 1 hour or so, add potatoes and carrots. You may have to add a little extra water so potatoes and carrots cook properly..