What you need:

2 lbs. stew meat, cubed
3 tablespoons olive oil
1 cup onion, sliced
1/2 cup chopped green pepper
1 large clove garlic
1/2 teaspoon salt
1/8 teaspoon pepper
2 cups beef stock
1, 8 oz. can tomatoes
1, 4 oz. can mushrooms
1/3 cup barbecue sauce
3 tablespoons cornstarch
1/4 cup cold water

How to make it:

Brown the stewing beef in a skillet in olive oil, remove and drain.
Saute the pepper, onion and garlic in the skillet in olive oil.
Add all the ingredients, except the water and cornstarch, to a 6 qt. crock pot and stir to mix well.
Cook on low setting for 8 to 10 hours.

Tips:

Just before serving, mix together the water and cornstarch. Add to the slow cooker and stir to thicken.  Serve over a bed of rice.