Step 1

Caramelizing the Onions: a. In a large skillet, heat 1 tablespoon of olive oil over medium-low heat. Add the thinly sliced onions to the skillet and cook, stirring occasionally, until they become soft and caramelized, about 20-25 minutes.

Step 2

Preparing the Au Jus Dip: Option 1: In a small saucepan, combine 1 cup of water, 2 tablespoons of unsalted butter, beef concentrate, and the reserved caramelized onions. Bring the mixture to a simmer over medium heat, stirring occasionally, and let it cook for about 5 minutes. Set aside.

Step 3

Option 2: In a small saucepan, combine 1 cup of water and the condensed onion soup. Stir in 2 tablespoons of unsalted butter and heat the mixture over medium heat until it comes to a gentle simmer. Remove from heat and set aside.

Step 4

Cooking the Burgers: Divide the ground beef into four equal portions and shape them into patties. Season the patties with salt and black pepper on both sides. In a separate skillet or grill, heat the remaining tablespoon of olive oil over medium-high heat. Cook the burger patties for about 4-5 minutes on each side or until they reach your desired level of doneness.

Step 5

During the last minute of cooking, add a generous amount of shredded mozzarella cheese on top of each patty to melt.

Step 6

Assembling the Burgers: Toast the burger buns lightly. Place each cooked burger patty on the bottom half of the burger buns. Top the patties with a portion of the remaining caramelized onions. Cover the burgers with the top half of the buns.

Step 7

Serving: Serve the Caramelized French Onion Burgers with the warm and flavorful Au Jus Dip on the side. Dip the burgers into the Au Jus before each savory bite, or pour it over the burger for an even more delicious experience.