Boursin Burgers with Crisp Prosciutto and Onion Jam

In a skillet over medium heat, add olive oil and thinly sliced onions. Saute for 8-10 minutes until onions have caramelized and turned golden. Next, add sugar, balsamic vinegar, rosemary and sage. Reduce to medium-low and continue to cook until liquid thickens and reduces by half—about 5 minutes. Remove from heat. The jam will continue to thicken a bit as it cools. Preheat a grill pan over high heat (or prep your outdoor grill). Then, form ground beef into six equal patties—about 1/3 pound each. Season with salt and pepper to taste.Tip: I try to handle the beef as little as possible when forming the patties. The warmth from your hands can begin to warm the fat in the meat which can result in drier, tougher burgers. When your grill pan is ready, cook the burgers to your desired level of doneness—about 4-5 minutes per side for medium. Flip your burgers only once for even cooking and for goodness sake please don't smoosh them with your spatula! Just let the poor little guys hang out and enjoy their last precious moments on this earth.Meanwhile, preheat a separate non-stick pan over medium heat. When it's nice and hot, lay strips of prosciutto in a single layer (like bacon). Cook for about 2 minutes per side or until the prosciutto has crisped up on both sides. Remove and let drain on a paper towel-lined plate.When the burgers have about 1-2 minutes left to cook, top each patty with a generous amount of crumbled Boursin cheese. Once the cheese has softened and started to melt, remove burgers from heat and let rest.Next, spread a little butter on both sides of each brioche bun. Then, place them face down on the hot grill pan and toast until golden brown. Remove and set aside.Finally, assemble the burgers. Place one burger patty on each toasted bun and then top with a few tablespoons of the balsamic onion jam, a slice of crispy prosciutto and a small handful of arugula. Then, devour.