Preheat your grill to medium heat (around 300F) for direct cooking.

Add a Dutch oven to heat up for 2 minutes over the fire. Add 2 tbsp of oil then your thinly sliced onion and season with salt and pepper.

Slow cook the onions, making sure to stir often with a wooden spoon, until they turn to a dark brown color (about 45 minutes of cooking).

When the onions are dark in color, deglaze the skillet with the brandy and white wine. Let simmer for 2-3 more minutes then add the beef broth, thyme and bay leaves. Cover and let simmer for 15 minutes.

Pull off the heat and strain the onions from the broth. Keep both the onions and the broth warm.

Heat your grill at high heat (around 400F) for direct cooking.

Add a cast iron skillet or plancha over the flames to heat.

Grab a handful of ground beef (around ¼ lbs… ish) and gently roll it into a ball. Repeat this for 6-8 balls or until you’re out of meat.

Get your skillet ripping hot (so it's gently smoking). Add a burger ball to the skillet. Place a piece of parchment over one ball and then firmly press with the spatula until the burger is 'smashed' on the skillet. Season the patty with salt, pepper and garlic. Let cook for another 1-1.5 minutes.

Carefully flip the burger patty over and then season the new side. Top with a slice of swiss cheese and some of the caramelized onions. Let melt for 1-2 minutes. Once melted, pull off and rest. Repeat for the rest of your patties.

Build each patty melt by starting with a thick slice of brioche, a slice of Swiss cheese, garlic mayonnaise, double beef patties, more garlic mayonnaise, and another brioche slice for the top.

Add the patty melts to the skillet and toast the bread till golden brown.

When the patty melts are done, pull off and slice. Add to a bowl some of the broth with some onions and garnish with chopped parsley. Dip the patty melts in the broth for serving. Enjoy!