Mix Ground beef,onion,garlic,parsley,salt,pepper,bread crumbs and milk.Mix well with your hands. Then make into patties. Then cook them on stove in some olive oil and untill just about done... then place in crockpot.
In pan you just cooked patties add gravy ,worcestershire sauce,pepper and ketchup.stir and get all that good flavor off bottom of pan. Just enough to heat and mix then add DRAINED mushrooms and mix . Then pour over patties in crockpot and cook on low for three hours.