Slice onions in half length wise and then slice to 1/8" thickness. I used a mandolin which made it fast and easy.
In a 12 inch skillet over medium-low heat add the olive oil and onions. Stir occasionally. Keep the heat at the medium-low setting, you don't want to get overzealous and use too hot of heat and then burn the onions.
Caramelizing onions takes about 40-45 minutes. You want the onions to be a rich brown, soft but not mushy.
Once the onions have caramelized, remove from heat. Set aside.
In a large bowl combine the cream cheese, sour cream, mayo, salt, and Worcestershire sauce. Using hand beaters, cream the mixture until it's a smooth consistency.
On a cutting board, slice the onions so that they are bite sized pieces.
Add the onions and fresh parsley to the cream cheese mixture and stir to combine. Serve with potato chips!