====== French Onion Burgers ======

===== Info =====
^Preparation Time:  |  40 min  |
^Serving Size:  |  4  |

===== Ingredients =====

**Caramilized Onions**
  * 2 Tbsp extra-virgin olive oil
  * 1 large onion, halved and thinly sliced
  * 1/2 tsp sugar
  * 1/2 tsp Kosher salt
  * 1/2 cup chicken broth
  * 1 tsp Worcestershire sauce

**Burger**
  * 1-1/2 lb ground beef
  * 2 Tbsp Worcestershire sauce
  * 1 tsp onion powder

**Finish**
  * 2 cups shredded gruyére cheese (approx 6 oz)
  * 2 Tbsp grated parmesan cheese
  * 4 burger buns
  * mustard (we prefer honey baked ham's honey mustard mayo)
  * lettuce (optional)

===== Instructions =====
  - Heat the olive oil in a large skillet over medium-high heat.  Add the onion and cook, stirring until it starts to brown, 3 to 4 minutes.  Add sugar and 1/2 tsp salt, reduce the heat to medium low and cook, stirring occasionally, until deep golden, 15 more minutes.  Add the chicken broth and 1 tsp Worcestershire sauce and simmer until the onion is tender and the liquid is almost evaporated, 8 minutes.
  - Preheat the grill and oven broiler.  Mix the beef, onion powder and the remaining 2 Tbsp Worcestershire sauce in a bowl with your hands.  Form into four patties, press an indentation in the center of each patty with your thumb, then grill until done.
  - Place the buns cut side up on a baking sheet.  Sprinkle with both cheeses and broil until melted, about 1 minute.  Spread mustard on the buns, add lettuce, burgers, and caramelized onion.