Ingredients:

• 2 tbsp olive oil;
• 4 cups chopped yellow onions;
• 1 tsp brown sugar;
• 2 tbsp balsamic vinegar;
• 1/2 tsp kosher salt;
• 1/2 tsp black pepper;
• 1 cup sour cream;
• 1/2 cup mayonnaise;
• 1/4 tsp worcestershire sauce;
• 1/4 tsp garlic powder

Method:
Heat olive oil in a large, thick-bottomed deep pot on medium high heat. Add the chopped onions and cook until translucent and starting to color, about 10 minutes. Stir in the brown sugar, balsamic, salt, and pepper. Lower the heat and cook gently, uncovered, for about 25 to 30 minutes, stirring occasionally, until the onions are nicely caramelized. Then set aside. Let cool a bit before adding to the other ingredients. In a medium bowl, mix together the sour cream and mayonnaise (a rubber spatula works well for this). Stir in the caramelized onions. Sprinkle with garlic salt and stir to incorporate. Stir in the worcestershire sauce.