How to Make the Ultimate French Onion Soup Burger
Do you believe it’s possible to have too much of a good thing? With this French Onion Soup Burger, we might be pushing the envelope (but in the best way).
Do you believe it’s possible to have too much of a good thing? With this burger, we might be pushing the envelope (but in the best way). This dish is a cross between classic French onion soup and your favorite fancy burger. Hearty beef patties are slathered with melty Gruyère cheese and a sweet caramelized onion gravy simmered in beef broth. With its nooks and crannies for hanging onto tangy mustard, toasted English muffins make perfect hamburger buns.
Burger patties tend to puff up when cooked. Creating a shallow dimple in the center of each helps them cook evenly and keep their shape.
If the burgers finish cooking before the onion, remove them from the pan and cover them loosely with foil to keep warm.
⅛ ounce fresh thyme
1 yellow onion
3 ounces baby arugula
12 ounces ground beef
1 tablespoon butter
1 tablespoon flour
8 ounces beef broth
3 slices Gruyère cheese
2 English muffins
2 teaspoons Dijon mustard
1 tablespoon + 1 teaspoon olive oil
1 tablespoon water
6″ small pan
10″ medium pan with lid
1. Prepare Ingredients
Strip thyme leaves, discarding stems. Peel onion, halve, and thinly slice. Halve lemon. Rinse arugula. Pat beef dry with paper towel. In a large bowl, whisk together juice of ½ lemon, 1 tablespoon olive oil, and ⅛ teaspoon kosher salt to make dressing.
2. Cook Onion
Heat butter in a small pan over medium-high heat. When butter is foamy, add thyme and onion and cook, stirring occasionally, until light brown and softened, about 5 minutes. Add 1 tablespoon water and reduce heat to medium. Cook, stirring continuously, until golden brown and very soft, about 5 minutes more.
3. Form Burgers
While onion cooks, combine beef, ½ teaspoon kosher salt, and pepper as desired in a large bowl. Using your hands, mix well. Divide mixture evenly and form into 2 patties, about ½-inch thick. Using your thumb, make a dimple in center of each (see Recipe Tip). Set aside.
4. Season Onion
Add flour to pan with onion over medium heat and stir vigorously until flour is no longer visible, 2-3 minutes. Pour over beef broth. Increase heat to high and bring to a boil, then reduce heat to medium high and simmer until sauce is thickened and reduced by ⅔, 2-3 minutes. Remove pan from heat. Season with ⅛ teaspoon kosher salt and pepper as desired.
5. Sear Burgers
While onion cooks, heat 1 teaspoon olive oil in a medium pan over medium heat. When oil is shimmering, add burgers and sear until browned on bottom, about 4 minutes. Flip and cook until medium, 3-4 minutes. Spoon over onion mixture, then top with Gruyère. Cover pan and cook until cheese is melted, 1-2 minutes more. Remove burgers with onion from pan.
6. Plate French Onion Soup Burgers
Add arugula to bowl with dressing and toss to coat. Halve English muffins crosswise. Wipe pan from burgers clean and add English muffins cut-side down over medium heat and toast until light golden, about 2 minutes. Spread mustard over cut sides. Top muffin bottoms with burgers. Finish with muffin tops. Serve with salad and any remaining onion mixture alongside.