Step 1

Preheat oven to 400 degrees F.

Step 2

Over medium heat, melt the butter in a skillet. Add the white, red, and sweet onion and sauté for 5 minutes. Add the green onions and brown sugar and cook for an additional 5 minutes, stirring every couple minutes.

Step 3

Add the white wine vinegar and worcestershire sauce. Cook for another 5 minutes, or until the onions are all very tender and turning a golden caramel color.

Step 4

Add the cream cheese to the skillet and stir to combine with the onions.

Step 5

Transfer the mixture to an 8x8 baking dish and stir in the sour cream and mayonnaise.

Step 6

Top with parmesan cheese and bake for 20-22 minutes or until golden brown on top.

Step 7

Serve hot with bread or crackers.