You can enjoy these scrumptious sandwiches in a jiffy. Make them for lunch or dinner. If you are craving French Onion Soup but it isn't quite the right weather, these sandwiches will satisfy your cravings.
2 1/2 T. extra virgin olive oil, plus additional for oiling grill or skillet
2 large onions, sliced
1 t. sugar
1 large or 2 small bay leaves
1/2 t. salt
1/4 t. pepper
2 t. Worcestershire sauce
2 large boneless, skinless chicken breasts, sliced across in half, pounded to a 3/4 inch thickness
8 oz. Gruyere or Swiss cheese
4 hamburger buns
2 T. Dijon mustard or your favorite
1 c. fresh spinach leaves
In a large skillet over medium heat, heat 2 1/2 tablespoons olive oil. Add onions, bay leaf, sugar, salt and pepper. Cook until onions turn a rich golden brown color and a few lightly crisp, stirring often. Remove from heat, discard bay leaf, and stir in the Worcestershire sauce. Set aside.
Preheat a grill or large skillet over medium-high heat with olive oil or non-stick cooking spray to prevent sticking. Cook chicken until no longer pink and the interior reaches 160°F, turning once, about 4 minutes per side.
Top each cooked chicken breast with 2 oz. cheese immediately after flipping.
Spread the bottom half of each bun with 1 1/2 teaspoons Dijon mustard. Top with fresh spinach, then the cheese-topped chicken, caramelized onions, and finally the top bun half.
Serve immediately.
Makes 4.