Cheddar Cheeseburgers with Caramelized Shallots

Ingredients

• 1 pound ground beef 90% lean
• 1 cup baby arugula 
• 2  garlic cloves minced
• 6 ounce hamburger buns toasted
• 0.5 teaspoon kosher salt divided
• 3 tablespoons mayonnaise light
• 1 tablespoon olive oil divided
• 2 cups shallots thinly sliced
• 0.5 cup sharp cheddar cheese shredded
• 1 tablespoon citrus champagne vinegar 

Equipment

• frying pan

Directions

1. Heat a nonstick skillet over medium-low heat.
2. Add 2 teaspoons oil; swirl to coat.
3. Add shallots and 1/4 teaspoon salt; cook 15 minutes or until golden brown, stirring occasionally. Stir in vinegar; cook 1 minute.
4. Remove from heat; keep warm.
5. Gently combine garlic and beef. Divide the meat mixture into 4 equal portions, gently shaping each into a 1/2-inch-thick patty. Press a nickel-sized indentation in the center of each patty.
6. Sprinkle evenly with the remaining 1/4 teaspoon salt.
7. Heat a large cast-iron skillet over medium-high heat.
8. Add the remaining 1 teaspoon oil to pan; swirl to coat.
9. Add patties, and cook for 3 minutes on each side or until desired degree of doneness. Top each patty with 2 tablespoons cheese; cover and cook 1 minute or until cheese melts.
10. Place 1/4 cup arugula on bottom half of each bun; top with 1 patty and one-fourth of shallots.
11. Spread about 2 teaspoons mayonnaise on top half of each bun; place on top of burgers.