Heat oil in dutch oven and brown pot roast for a few minutes on each side
Put soup mix, bay leaf, 1 cup water and pot roast in slow cooker and set on low setting for 8-10 hours
Remove pot roast and strain liquid, discarding onion bits after pressing liquid from them
Make gravy by melting butter in a fry pan and adding flour until you have a nice paste consistancy. Add liquid from pot roast slowly allowing it to thicken over medium heat. If it is too thick, add more water- if it is too thin, mix tablesppon of water and cornstarch and add to gravy.
Slice pot roast and serve with mashed potatoes and baby carrots with gravy poured over everything.