Lightly brown beef and onion in butter in stew pot. Add carrots, celery, lemon juice, bay leaf, mushrooms, green pepper, and Redi-Base. Pour in beer. Cover and simmer over low heat until meat is tender, about 1 1/2 hours. (Add water, if necessary, to replace any liquid that has evaporated.)
Add potatoes during last 45 minutes of cooking.
Place meat and vegetables on heated platter.
Strain liquid remaining in pan. Blend flour and water to smooth paste. Stir into liquid and cook until thickened. Pour sauce over meat and vegetables.Servings: 6 to 8