Beef Cooked in Beer and Onions

2 lbs. chuck or round, cut into 6 to 8 slices
Cookies Flavor Enhancer, to taste
2 T. butter
2 T. oil
5 to 6 medium onions, peeled and thinly sliced
1 1/2 T. flour
2 cups dark beer

Season the beef with Flavor Enhancer. In an oven-proof covered casserole, melt the butter and oil. Brown the meat in the fat over high heat and remove. Add the onions, lower heat, and cook slowly until soft, stirring frequently. Add the flour and stir to blend. Keep stirring over moderately high heat until flour begins to brown. Pour in the beer. Stir until thickened and simmering. Return the browned beef to the pan. Cover and cook over low heat until beef is very tender, about 2 1/2 hours. Check often to make sure that there is enough liquid to cover the meat. Add more beer or water as needed. Can serve hot with rice or buttered noodles.