this is how it's supposed to be

Ladies and gentlemen, this has got to be the best mac + cheese I've ever made.

What I should really do is go back to all of the posts where I've made similar declarations and do a taste-off to decide once and for all. However, I would be hard-pressed to find one that rivals the flavor bomb of this one. The soubise is worth the extra time and blender cleaning. The caramelized onion flavor is as delicious as it is impossible to place, making you look like a culinary magician.

The sweetness of the onions really plays nicely against what are otherwise fairly earthy spices - cayenne, smoked paprika and that divine fish sauce. The extra oven time gets the pasta so nice and creamy, while the additional panko and Parmesan topping crisps up perfectly. This is everything mac + cheese is supposed to taste like.

Mac + Cheese with Soubise
adapted from Serious Eats

For the soubise:
4 T. butter, divided
1 medium onion, sliced
salt
3 T. all-purpose flour
1 1/2 c. milk
1 T. white wine vinegar
3 T. vermouth
1 T. fish sauce
1/4 t. ground black pepper
1/4 t. cayenne
1/2 t. smoked paprika

12 oz. pasta
1 pound Comté, Gruyère, Emmenthaler, Cheddar, or a combination of these cheeses, grated
1/4 c. grated Parmigiano-Reggiano
1/2 c. panko bread crumbs
2 T. butter, melted

1. Make the soubise: Melt half the butter in a medium saucepan over medium heat and add the onions and a four-fingered pinch of salt. Cook, stirring until the onions are nicely caramelized.

2. Add the remaining butter and stir to melt. Add the flour, stir to mix, and cook until the mixture has taken on a toasted aroma, a few minutes. Gradually whisk in the milk and stir with a flat-edged wood spoon or spatula, to make sure the flour doesn’t stick to the bottom of the pan, until the sauce comes up to a simmer and thickens, a few minutes more. Stir in a three-finger pinch of salt, the white wine vinegar, vermouth, fish sauce, black pepper, cayenne and smoked paprika. Transfer the sauce to a blender and process until puréed, or purée in the pan with a hand blender. Return the sauce to the pot and add the cheese gradually, stirring until melted.

3. Cook the pasta just until al dente, drain, the add it to the soubise. Toss to coat. Transfer to a greased 9x13 pan.

4. Preheat the oven to 425°F.

5. Sprinkle the pasta with the Parmigiano-Reggiano. In a small bowl, toss the panko with the remaining melted butter and spread this over the top. Cover with aluminum foil and bake until heated through, about 30 minutes (longer if it has been chilled in the refrigerator). Remove the foil and bake until the cheese is nicely browned, or turn on the broiler/grill and broil/grill until the top is browned, 15 to 20 more minutes. Serve immediately.