- Melt the butter in a frying pan over medium-low heat and add in the onions. Season with the salt and cook until lightly caramelized, about eight minutes. Add in the maple syrup and continue cooking until the onions are jammy and well caramelized, about 10 to 15 minutes. Remove from the heat and set aside.
- Meanwhile, in a large bowl, combine 1/4 cup of the cooled maple caramelized onions, the beef, egg, bread crumbs, parsley, thyme, summer savory, pepper, and mustard. Using your hands, mix just until combined. Divide the beef into four evenly sized pieces and press into rounds about 2.5 centimeters thick. Sprinkle the outsides of the patties with more salt to season.
- Preheat your grill or a skillet to medium/medium-high.
- Cook the burgers to your desired doneness. I typically do four minutes on the first side and three minutes on the second, and then I top the burgers with cheese and cook them for an additional one to two minutes.
- Allow the burgers to rest for five minutes before placing in the buns and dressing them with all of the fixings you can think of, including the rest of those maple caramelized onions.
Note: For the tastiest burgers that can be cooked to any doneness, freshly ground beef from the butcher is the way to go. And if you can’t find summer savory, add another teaspoon of finely chopped fresh thyme.