French Onion Soup and Mac and Cheese are two of the great food loves of my life, and I felt like it was high time they meet. Not all food mashups are meant to be, but this is one where the two dishes truly complement each other – the rich sweetness of the onions goes so well with all that salty, creamy cheese and the carby comfort of macaroni does what it does best… fill you right up, stomach and soul.
1 lb macaroni
For the onion mix-in:
3 tablespoons unsalted butter
3 large white onions, thinly sliced
2 teaspoons Worcestershire sauce
1 teaspoon dried thyme
3/4 cup dry sherry
1 1/2 cups beef broth
For the sauce:
4 tablespoons (1/2 stick) unsalted butter
4 tablespoons all-purpose flour
2 cups whole milk
3 cups Gruyere or Swiss cheese, grated and divided
1 1/2 cups mozzarella cheese, grated and divided
1/2 cup Panko breadcrumbs
Kosher salt and freshly ground black pepper, to taste
Preheat oven to 350°F and grease a 3-quart casserole dish with butter or nonstick spray. Set aside.
Cook macaroni 2-3 minutes less than package directions indicate. Drain and set aside.
Meanwhile, make the onions:
In a large skillet, heat the butter over medium-low heat. Add the onions, Worcestershire, thyme, and some salt and pepper and cook, stirring frequently, until onions are lightly golden, about 15 minutes.
Add the sherry and bring to a simmer, stirring until little liquid remains, about 2 minutes. Stir in beef broth, bring to a simmer and cook until nearly evaporated, about 5 minutes. Adjust seasoning as needed and set aside.
While onions cook, make the béchamel sauce:
In a large saucepan, melt the butter over medium heat. Add the flour and stir constantly for 2 minutes.
Gradually whisk in milk, and cook until thickened, about 5 minutes.
Stir in 2 1/2 cups of Gruyere and 1 cup of the mozzarella cheese until melted. Season to taste with salt and pepper.
Stir in macaroni and half of the onion mixture. Pour into prepared baking dish.
Spoon remaining onion mixture over macaroni and top with remaining cheese and breadcrumbs. Bake until golden brown and bubbly, 30-35 minutes. Let cool 5 minutes before serving.