Cut bacon into 3cm squares.
Heat butter in a heavy frypan and saute beef over high heat to brown. Cook in 2 or 3 batches to prevent overcrowding. Transfer meat to a casserole dish.
Add onions, bacon and mushrooms to pan and cook gently 3 minutes to soften. Add wine, beer and stock, bring to the boil and pour over the beef.
Cover and cook for 1 1/2 to 2 hours in oven at 180C/350F until beef is tender.
Pour off liquid into a pan, bring to the boil and thicken with cornflour dissolved in a little cold water. Stir in chopped parsley and pour back over beef.
Great winter dish