My Caramelized Onion And Shallot Dip

• 3 large yellow onions, thinly sliced
• 2 large shallots, thinly sliced
• 2 Tbsp butter
• 1 Tbsp olive oil
• 1 Tbsp sherry vinegar
• salt & pepper
• 2 cups sour cream
• 1 cup mayonnaise
• garlic powder
• celery salt
• ~2 tsp worcestershire sauce
• ~1 Tbsp chile powder

1. Heat the butter and oil in a large skillet over medium high heat. Add the onions and shallots, salt and pepper, and mix well. Turn the heat to medium low, cover, and allow the onions to sweat and soften for 10-15 minutes. Remove lid, and continue to cook for 40 minutes until the onions are dark brown in color and still moist, stirring every 10-15 minutes. Reduce the heat to low, and continue cooking 15 minutes more, stirring frequently, until a deep brown is reached. Add the sherry vinegar, mix well and allow to cool.
2. Combine the sour cream, mayo, and the spices and worcestershire sauce, and mix well. Add the onion mixture, mix well and taste. Adjust seasonings as needed.
3. Chill for at least one hour.

yellow onions, shallots, butter, olive oil, sherry vinegar, salt, sour cream, mayonnaise, garlic, celery salt, worcestershire sauce, chile powder

Taken from www.epicurious.com/recipes/member/views/my-caramelized-onion-and-shallot-dip-52683751 (may not work)