Roast Beef & French Onion Grilled Cheese

It's Cold Outside...And when it's cold outside...one should have a nice quick fix of a meal to eat inside!
So my answer to that on a cold day is this bit of what I like to call Neuvo Americana comfort food.
The Roast Beef & French Onion Grilled Cheese sandwich.

According to Women's day, where I found this recipe-Nutty, gooey Gruyère is even tastier when melted on top of savory roast beef and sweet, fragrant sautéed onion.

INGREDIENTS: 

• 1 tablespoon(s) olive oil
• 1 small onion, sliced
• 1 teaspoon(s) thyme leaves
• Kosher salt
• Pepper
• 4 slice(s) (1/2-inch-thick) rye bread
• 1 tablespoon(s) melted unsalted butter or olive oil
• 1 tablespoon(s) whole-grain mustard
• 2 ounce(s) Gruyère cheese, grated
• 2 slice(s) roast beef

DIRECTIONS:
 Heat olive oil in a medium skillet over medium heat. Add onion, season with 1/4 teaspoon each salt and pepper, and cook, covered, stirring occasionally, for 12 minutes. Reduce the heat to medium-low, stir in thyme leaves and cook, uncovered, stirring occasionally, until the onions are golden brown, 15 to 20 minutes more (add 1 tablespoon water to the skillet if the onions start sticking).

 Brush one side of each slice of bread with butter or oil. Form sandwiches with the bread, whole-grain mustard, Gruyère cheese, roast beef, and the onion mixture. Cook the sandwiches, covered, until the bread is golden brown and crisp and the cheese has melted, 4 to 5 minutes per side.

Enjoy!  Eat well my friends!