Do you mean a "roast" like a piece of meat or "to roast" as in "roasting peppers"? Meats are roasted in an oven, not on the stove. Peppers or nuts can be roasted in a frying pan. If you are making pot roast, thats a "brasied" dish, not a roasted dish.
For braising, it should be seared on all sides in frying pan and then brasied in a crock pot, on the stove, or in the oven. Liquid should be added. If done on the stove or oven, a pot with a lid should be used. It should braise at a low temperature for a long time. Set the crock pot and stove on low. If done in the oven, set it at 300 F. It'll take 2.5 -4 hours, depending on the size of the meat. Test it with a fork, it should be very tender but not falling apart.
