French Onion Mac and Cheese

01Method

1. 1

   Melt 2 tablespoons of the butter together with the olive oil in a large skillet over medium heat. Add the sliced onions and stir for 1 minute. Lower the heat to medium-low and cook, stirring from time to time, until the onions turn a deep golden brown, approximately 40 minutes.

2. 2

   Stir in the thyme, Worcestershire sauce, and sherry, letting the liquid cook off for about 3 minutes. Season with a portion of the salt and pepper, then transfer the onions to a bowl and set the skillet aside.

3. 3

   Bring a large pot of water to a boil, salt it, and cook the pasta until just tender, about 6 minutes. Drain and set aside.

4. 4

   Preheat the oven to 375°F (190°C) and grease a 9x13-inch baking dish with butter.

5. 5

   Return the skillet to medium heat and melt the remaining butter. Whisk in the flour and stir for 2 minutes. Pour in the milk and bring to a gentle simmer, stirring frequently. Season with the remaining salt and pepper, cook for 5 minutes, then stir in most of the Cheddar and half the Swiss cheese. Remove from heat.

6. 6

   Fold the caramelized onions and cooked pasta into the cheese sauce, then transfer everything to the prepared baking dish. Tear the baguette slices in half and arrange them over the top, then scatter over the remaining cheeses.

7. 7

   Bake until the top is golden and the filling is bubbling, about 25 minutes.