I'm told that I make a great pot roast.

Number one, make sure it is a good quality piece of meat.
I always buy an oven roast because it is better to start with.

Melt half a stick of butter in a 6 quart pot.
Turn the heat up between medium and medium high.
Put the roast in and brown it on all sides to seal in the flavor. Don't burn it!

When it is brown on all sides, pour in about three inches of water.
Add beef boullion cubes (three)
Bring it to a boil.
Turn the heat down to medium and keep checking it to make sure it doesn't run out of water. That will ruin it.
Try to keep at least three inches of water in the pot at all times.
I always keep a small pot of water on another burner to add as needed so it doesn't cool the water down too much.
Depending on the size of the roast, assuming it is three pounds or so, you will be tied up cooking this for at least three hours.
When it gets to where you can cut off a bit with a table knife, it is probably done. I don't like tough pot roast, so I let it cook until it starts to fall apart.

About 3/4 of an hour before it is served, peel and add potatoes, carrots and onions. If it is done right, the whole mess should all be done at the same time. The key is, pay attention and keep an eye on it..