French Onion Soup Burgers
1/4 cup olive oil
5 cups halved and thinly sliced sweet onions
1 1/2 teaspoons fresh ground black pepper
3 tablespoons chopped fresh thyme, divided
2/3 cup dry white wine
2 1/4 pounds 80% lean fresh ground beef (preferably organic)
2 cloves garlic, minced
2 cups grated Gruyere cheese, divided
2 tablespoons chopped fresh basil
1 teaspoon kosher salt
Olive oil cooking spray
6 crusty French rolls (large enough to hold 3 to 4 inch burger patties), split
1/2 cup low sodium beef stock
On a side burner or directly on the open grill, preheat the oil in a grill safe sauté pan over medium heat. Add the onions and the pepper and sauté for 15 to 20 minutes (or until the onions are golden and just beginning to stick). Stir in 2 tablespoons of the thyme. Stir in the wine. Simmer for 5 minutes (or until the wine has evaporated). Remove from the heat, cover, and set aside.
Preheat the grill to medium high. Gently combine in a mixing bowl the ground beef, the garlic, 1/2 cup of the cheese, the basil, the salt, and the remaining 1 tablespoon of thyme. Form the beef mixture into six equal patties, about 1/2 inch thick, without overworking the meat. Press a slight indentation into the center of each patty. Spray the patties on both sides with the cooking spray. Grill the patties over direct heat for 2 to 4 minutes per side, or until just shy of medium rare to medium. Divide the remaining shredded cheese evenly among the patties to melt, with the grill closed, during the last two minutes of cooking. Remove the patties from the heat and tent with foil.
Brush the insides of the rolls with the beef stock (you might not use it all). Spray the insides of the rolls with the cooking spray and toast on the grill over indirect heat (or on a raised rack). Remove from the heat and assemble the burgers. Place one patty on each bottom bun. Top each burger with equal amounts of the onions and finish with the top buns. Serve the burgers cut in halves and secured with unadorned skewers or toothpicks.