Perfect Pot Roast In A Bag - cooking recipe

Ingredients

4 lbs beef shoulder (it must be this cut!)
1 large onion, sliced
1 cup beef stock
1/2 cup flour
salt and pepper
3 large carrots (cut into 2 in pieces)
4 large russet potatoes (peeled and quartered)
2 tablespoons olive oil
1 oven cooking bag

Preparation

Turn oven to 325 degrees.
Shake salt and pepper into the flour. Put flour on paper plate and then place meat on the plate - turning to cover all sides with the flour. In a pan hot with about 2Tbl olive oil, brown meat well on all sides. This should take about 10 minutes.
Prepare roasting bag by shaking 1 TBL flour in bag, set bag in 2 in deep oven safe pan.
Place a few onion slices in bottom of bag, followed by the browned roast. Place remaining onion slices on top of roast. Pour the beef stock over the Roast and seal the bag. Cook on middle rack of oven for 2 hours.
After 2 hours, Remove all but 1/2 C of roast juices from pan (I used to make gravy) Place sliced carrots around roast, place potatoes on top of carrots, reseal bag and cook an additional 2 hours.