Melt the butter in a small skillet over medium heat.

Add the onions.

Cover and cook for 10-15 minutes, stirring occasionally, until the onions are soft.

Then uncover and cook for an additional 5 minutes until the excess liquid cooks off.  Deglaze the pan with the beer.

Mix together the sauce ingredients in a small bowl.  Cover and refrigerate until ready to use.

Preheat a grill over medium heat (approximately 350-400 degrees F).

Form the beef into 4 patties that are approximately ½ pound each.

Place on the grill over direct heat. Season the patties with salt, pepper and garlic powder.

Cook for 5-6 minutes per side until the patties reach an internal temperature of 165 degrees F.

Place a slice of cheese on the patties for the last minute of the cooking time to melt the cheese.

Butter the pretzel buns and place them on the grill for approximately 1 minute to toast the buns.

Remove the buns. Spread the burger sauce on the buns.

Serve the patties on the buns topped with the caramelized onions and enjoy!