carmelized onion stuffed burger

Ingredients

2 tbls. butter 
medium vidalia, or any sweet onion
1 tbls packed brown sugar
1 tsp. balsamic vinegar
3 tbls. gorganzola (or feta) cheese (or more if needed)
one pound or more of ground sirloin, or chuck

Instructions

melt butter and cook onions, brown sugar, and vinegar ,until the onions are cooked.Set aside.(can be cooked earlier)Make your burger and try not to handle it too much.(this will keep it from getting tough)Make a small indentation on top, and stuff with the onions and cheese.about a tablespoon of onions and a teaspoon of cheese) Cover the burger with enough beef to close the indentation. Grill to desired doneness. Top with a teaspoon of the carmelized onions, and any other condiments desired