Ken
Pot roast is not a roast nor does it require a pot.
It is any cheap long muscle of cow, cross cut and braised.
What many call a pot roast is really the terrible curse of the British known as boiled beef.
Rub with kosher salt and whatever spice you like.
Carmalize the outside of a the roast, saute onion and garlic, add braising liquid (wine, water, juice, beer, whatever you want the gravy to taste like) and de-glaze the browning pan. Reduce liquid by half.
Bake at 200 in a vessel with lid or meat and liquid in a tight foil envelope or cooking bag.
The meat has to reach 180 to melt the collagen. Should take a bout 3-4 hours depending on the size. Let it rest before serving to reabsorb some of the braising liquid.
If you cook it faster at higher temps yer gonna boil it.
Endless variations with spice, beverages, fruits and veggies in the braising liquid.