Caramelized Onion Dip

Ingredients
    •    3 large yellow onions
    •    1 Tbsp butter
    •    1 Tbsp olive oil
    •    1 tsp salt
    •    1 Tbsp brown sugar
    •    1 Tbsp (or a touch more) cognac
    •    1/2 cup mayonnaise
    •    1/2 cup sour cream
    •    1 1/2 cups grated Gruyere cheese (about 6 ounces)
    •    1/2 cup grated Parmesan cheese
    •    1/2 tsp dried thyme, crush with your fingers as you add it
    •    1/2 tsp garlic powder
    •    1 tsp coarse salt
    •    1 tsp cracked black pepper
Instructions
    •    Peel the onions, slice and chop into smaller pieces.
    •    Combine the butter and oil and heat over medium heat in a large Dutch oven. Add the onions and cook until they start to soften, stirring frequently, about 5 minutes.
    •    Add the salt and brown sugar to the pan and stir well.
    •    Continue to cook the onions, uncovered, over medium heat, until they begin to caramelize, approximately 1 hour, continuing to stir every so often. The onions will release moisture first, then SLOWLY turn from golden to brown.
    •    When onions have reduced and turned a deep golden brown, you can deglaze the pan with the cognac by scraping up any browned bits from the bottom of the pan. Remove pan from the heat to cool.
    •    Preheat the oven to 375 degrees Farenheit.
    •    Combine mayonnaise, sour cream, cheeses, thyme, garlic, salt and pepper into a bowl. Fold in the cooled onions.
    •    Spread mixture into a gratin dish, cast iron skillet, or other oven safe baking dish.
    •    Bake for 25-30 minutes, or until the dip is bubbling and golden on top.
    •    Serve hot with thin slices of toasted sourdough or baguette. Enjoy!