French Onion Burgers- onion seasoned ground beef patties are topped with gruyere cheese, caramelized onions and garlic Dijonnaise and served on brioche buns with a little baby arugula. Not your average burger!
Heat olive oil and butter in a large nonstick skillet. Add onion and cook over medium to medium-low heat until golden, about 25 minutes. Be sure to stir them frequently so they don't burn.Stir in balsamic vinegar and thyme and season with salt and pepper. Set aside.
In a small bowl, stir together dijonnaise ingredients. Refrigerate until needed.
In a medium bowl, mix together ground chuck and onion mix. Shape into 4 patties.
Heat a cast iron skillet over medium-high heat. When hot, add patties and cook 4 minutes. Flip over and cook another 3 minutes.Divide shredded gruyere between the burgers. Turn heat to low and cover skillet for 1 minute to melt cheese.
Place some arugula on the bottom of each bun. Top with Dijonnnaise, a burger patty and onions.Top with bun tops and serve.