This Baked Caramelized Onion Dip is an essential appetizer recipe for cold weather and/or holiday entertaining. Whether you're watching the big game or celebrating with family and friends, this dip will be a winner every time!
In a large non-stick skillet (or cast iron pan) melt the butter and olive oil over medium heat. Add the sliced onions and cook for about five minutes stirring as necessary. Then add in the thyme, sugar, and half of the salt.
Stir to combine and cook until the onions are soft and golden brown. This will take about 20 minutes. Remove the onions from the heat; add in the balsamic vinegar. Stir to combine. Set aside to cool slightly.
Preheat your oven to 400 degrees F.
In a large bowl, stir together the cream cheese, parmesan cheese, gruyere cheese, sour cream, mayonnaise, half-and-half, garlic, black pepper, and remaining salt. After the onions have cooled slightly, stir them into the cheese mixture to combine.
Spray a medium cooking dish with cooking spray and then fill it with your cheese and onion mixture.
Bake for about 25-30 minutes or until golden and bubbly.