Cook just until the onion starts to get translucent and meat is
browned on outside, but not cooked through. This will help keep the
meat moist while it cooks in the crockpot. You can skip this and just
dump everything into crockpot, but it won't be as moist and tender
when it is done.
Mix together- milk, mushroom soup, worcestershire sauce, and cream
cheese. Stir well. If you plan on using sour cream, do that here. Put
sauce mixture and meat and onions in crockpot, put lid on, and cook
on low for 4 - 5 hours. You can stir occasionally.