"This homemade French onion dip features deeply caramelized onions, balsamic vinegar, sour cream and mayonnaise. Easy and SO delicious!..."
INGREDIENTS
•
3 tablespoons unsalted butter 2 pounds yellow onions (about 3 medium), finely chopped 1/2 teaspoon salt 1/2 teaspoon black pepper ⅛ teaspoon cayenne pepper 4 tablespoons water, divided 2 1/2 teaspoons balsamic vinegar 1 cup sour cream 1/2 cup m