In a skillet over medium heat - add about 1 Tablespoon of oil - add onions - cook for about 12 minutes - you really want them brown and soft. Lightly salt and pepper
In another skillet - cook the burgers - add rosemary to the meat season with a little garlic powder - it will take about 10 - 15 minutes to cook the burgers so plan accordingly
Toast the buns
In a bowl - combine the following well - mayo, Dijon, and lemon juice
Once the burgers are cooked top with cheese
Place the mayo mixture on the bottom of each bun then arugula, burger then top with the top bun
Enjoy!
Recipe by Budget Savvy Diva at https://www.budgetsavvydiva.com/2015/04/burger-recipe/