Cranberry Onion Pork Recipe

I don't know where Mom got the recipe. She heard it on a PBS show - I think.
Pork goes best with this, but I believe you can use beef as well.

Pork - we've used a pork loin roast of (approx.) 2-3 lbs as well as bone-in country style pork ribs
1 can whole berry cranberry sauce
1 pkt Onion soup mix

*this works best in the oven with cast iron.
Dump everything into a high sided cast iron pot  (we use one with a lid)
Only if using a pork loin roast, add a small amount of water. Adding water to the ribs just makes the sauce watered down.
 *what temp?* I'm guessing 350°f
*How long* until the meat is tender