Prep Time: 5 minutes
Cook Time: 15 minutes
Make-Ahead: Onions can be cooked up to 2 days ahead, cooled, covered, and refrigerated. Rewarm onions, covered, over medium-low heat before using.
1 tbs. butter
1 lb. yellow onions, peeled, thinly sliced
1 tbs. Bourbon whiskey
1 tbs. light brown sugar
Four 5-oz. frozen beef burger patties
4 slices Muenster cheese
1/3 cup mayonnaise
1 tbs. Dijon mustard
4 hamburger buns, toasted
1 1/2 cups (not packed) baby arugula leaves
- In a large nonstick skillet over medium-high heat, melt butter. Add onions and cook, stirring often, for 15 minutes, or until caramelized and tender. Remove pan from heat and stir in whiskey and sugar. Season with salt and pepper. Keep Bourbon onions warm.
- Heat another large nonstick skillet over medium-high heat. Season patties with salt and pepper. Add frozen patties to skillet and cook about 4 minutes, or until browned. Turn patties over and top each with slice of cheese. Cook about 4 minutes for medium-rare doneness.
- In small bowl, whisk mayonnaise and mustard. Spread buns with mayonnaise mixture and mound arugula on bottom halves.
- Place patties on bun bottoms. Top with generous amount of Bourbon onions and bun tops and serve.