Blue Cheese Burgers with Balsamic Caramelized Onions

Sweet, salty and savory, this totally amazing burger will make you the star of your next barbecue and dad's best friend this coming Father's Day. You'll have plenty of caramelized onions for this recipe; use them to top a turkey sandwich or stir into some sour cream for a quick and tasty onion dip. This recipe makes 4 meal-sized burgers or 8 sliders.

PREP TIME: 10 minutes
COOK TIME: 40 minutes

Ingredients
For the caramelized onions:
1 tablespoon olive oil
1 tablespoon butter
3 large red, yellow or sweet onions
2 tablespoons brown sugar
2 tablespoons balsamic vinegar

For the burger patties:
1 pound ground beef, at least 15% fat
1 clove garlic, minced
1/2 small yellow onion, minced
2 teaspoons ketchup
2 teaspoons Worcestershire sauce
1 teaspoon salt
1 teaspoons pepper

Remaining ingredients:
4 good-quality hamburger buns, split
4 ounces blue cheese, divided
2 tablespoons mayonnaise

Directions
Make the meat mixture: In a large bowl, combine all burger patty ingredients and mix gently with your hands to combine. Do not over mix or the meat will become mushy when cooked. Cover and let rest in the refrigerator while you make the onions.

Make the balsamic caramelized onions: Heat butter and oil to medium in a large, heavy skillet. Add the onions and toss to combine. Cook for 15 minutes, stirring occasionally. Reduce heat to low, add vinegar and sugar and cook for another 10 minutes, until the sugar caramelizes and the vinegar reduces. Remove from heat and set aside.

Make the burger patties: Heat your grill to high. Divide the meat mixture into 4 equal portions, forming the patties loosely with your (clean) hands. Cook for 2 minutes and flip. Cook for two more minutes and reduce heat to medium (or move patties to a cooler spot on a charcoal grill). Grill 2-3 more minutes for medium-rare burgers, 3-4 minutes for medium and 5-5 for well-done.

The last minute of cooking the burger patties, put the bun tops and bottoms, split side down on the grill to toast them up for about a minute.

To assemble the burgers, spread some mayonnaise on the bottom of each bun and top with a burger patty. Add a fourth of the blue cheese to each burger and top with a big scoop of caramelized onions. Serve immediately.