French Onion Burgers

From Cooking Light. Each burger on a bun is about 340 calories. you could make it even less by making this into six burgers and using low calorie buns.

• Ready In: 10 mins
• Serves: 4

Ingredients

• 2  teaspoons  vegetable oil
• 2  cups  chopped onions
• 1  lb  ground round
• 1⁄4 teaspoon pepper
• 1  large  egg white, lightly beaten
• 1  teaspoon salt
• 4 (1 1/2ounce)  French rolls or 4 (1 1/2ounce)  hamburger buns, split and toasted
• 4  teaspoons  fat-free French dressing or 4  teaspoons  fat free blue cheese dressing

Directions

1. Heat oil in a 12-inch cast-iron skillet over medium-high heat. Add onion; sauté 10 minutes or until tender. Spoon onion into a bowl; let cool.
2. Add beef, pepper, and egg white to onion, and stir well. Divide beef mixture into 4 equal portions, shaping into 3/4-inch-thick patties.
3. Sprinkle salt evenly over surface of skillet. Heat salt in skillet over high heat 2 minutes. Add patties; cook 5 minutes on each side or until done. Place patties on bottom halves of rolls; top each with 1 teaspoon French dressing and top halves of buns.