Corned Beef and Cabbage (from Lacey for St. Patrick's Day)

4 1/2 lbs corned beef (with seasoning packet)
1 onion peeled and left whole
1 small head cabbage
6 potatoes quartered
4 large carrots sliced
2 TBLS butter (optional)
1/4 cup fresh parsley (optional)

1. In a 6 quart Dutch over, place the beef and seasonings, onion. Fill pan with water to cover everything plus 1 inch. Bring to boil and cook for 20 minutes. Skim off any residue that floats to the top. Reduce heat to a simmer and cook for 2 to 3 hours, until meat can be pulled with fork.

2. Once meat is done, add cabbage, potatoes and carrots, pressing them down into the liquid. Simmer until potatoes are tender. Skim off any oil that comes to surface. Stir in butter and parsley. Remove from heat.

I just use this as guide I don't follow it directly. I also don't use the butter and parsley.