Corned beef is really simple,
Chop up some onions and throw them in, put in a splash of vinegar, some mixed spice, a little brown sugar, A lemon cut in quaters, rinse the beef off in cold water, pop it in your slow cooker and then fill with hot water until the meat is covered, slow cook until dinner time.
I'm not usually one to measure my ingredients so sorry I can't give you exact measurements, I just throw it all in.