4large yellow onionssliced in rounds 1/4-inch thick
2tablespoonsbutter
2tablespoonsolive oil
1tablespoonbrown sugar
For the Beef Patties:
1-½poundlean ground beefI like the 80% from grass fed beef
1teaspoonkosher salt
½teaspoonfreshly ground black pepper
2large onionssliced in 1/4-inch rounds
2tablespoonsmayonnaise
2teaspoonsDijon mustard
4ouncesblue cheeseslices or crumbles
4large brioche burger buns
Instructions
For the Caramelized Onions:
In a large Dutch oven or heavy-bottomed skillet over medium-low heat, add the oil and butter and heat until melted. Add the onions, breaking up the rings and toss to coat the onions completely.
Allow the onions to cook, without a lid, stirring every 2-3 minutes. Allow the onions to cook for about 10 minutes until you see some browning. Sprinkle the onions with the brown sugar and toss to combine.
Continue to cook the onions another 15 minutes or so, stirring occasionally, allowing them to get very brown, you may need to reduce the heat to prevent burning.
When the onions are soft (but not so soft they are mushy) and caramelized remove the pan from the stove and transfer the onions to a serving dish.
For the Beef Patties:
If you are using an outdoor grill, pre-heat the grill and season the grill grates.
Add the beef to a large bowl and sprinkle it with salt and pepper and mix it together with your hands. Mix it just enough to combine as over mixing will make the beef tough.
Form the seasoned meat into four equal patties of about 4 inches in diameter that are a little thinner in the center. This will keep the patties from ballooning up.
Place the beef patties on the grill or a hot skillet over medium-high heat. Cook the patties for about 8 minutes on the first side. Flip the patties over and add the blue cheese. Cook the patties to an internal temperature of 160° with a meat thermometer, about another 5 minutes.
While the patties are cooking, place the brioche buns on the cooler side of the grill and toast them slightly, they should be done before the beef patties are finished cooking. Alternatively, you could toast the buns on a skillet.
Remove the patties from the grill, spread the mayonnaise and mustard on both sides of the bun. Add the beef patties and pile on the caramelized onions and the bun top. Enjoy!