Marinade (optional): Poke roast with large serving fork and spread marinade over both sides of roast. Refrigerate for about 1/2 hour prior to cooking.
Brown roast in oil in a skillet. Next, place roast in a large pot with chopped potatoes, carrots, mushrooms, and onions. Add both cans of mushroom soup and both cans of water. Salt can be added to vegetables if desire. Cover with lid or foil.
Bake at 325 degrees F for 2 and 1/2 hours. Internal temp should be 145 degrees F for 3 minutes.