Part 3/7:
The foundation for this culinary creation begins with caramelized onions, a key ingredient that adds sweetness and depth to the burger. By thinly slicing half of a large onion and slow-cooking it in a mix of olive oil and butter, a rich caramelization process ensues. To enhance their flavor, a splash of beef broth is added, allowing the onions to soak in additional savory goodness. This elevates the onions’ natural sweetness, making them an irresistible topping for the burger.