Serves 8 to 10, family-style
1 gallon water
2 tablespoons plus 1 teaspoon kosher salt
16 ounces dried macaroni
3 tablespoons butter
3 tablespoons all-purpose flour
3 cups half-and-half, room temperature
1 pound grated Monterey Jack cheese
1 cup milk
1/2 teaspoon freshly ground black pepper
1/4 teaspoon cayenne pepper
6 ounces blue cheese, crumbled
Bring the water to a boil in a large stockpot over high heat. Add 2 tablespoons of the salt and stir to dissolve. Add the macaroni, reduce the heat to medium-high and cook the macaroni for about 12 minutes, or until cooked but still firm. Remember, the noodles are going to cook more when you bake the dish. Strain the macaroni and rinse them in a bowl of cold water and a few ice cubes until cooled. Drain and cover loosely. I do not recommend oiling the macaroni noodles.
Preheat an oven to 400 degrees. Lightly butter a 9x13-inch casserole dish.
Melt the butter in a heavy-bottomed saucepan over medium heat. Whisk in the flour.
Cook over low heat for 2 minutes. Add 1/2 of the half-and-half and whisk vigorously as it thickens to a smooth paste. Use a spatula to release any mixture that might be stuck in the bottom edge of the pan. Whisk again until smooth and thickened. Add the remaining half-and- half and whisk constantly, slowly bringing the sauce up to a simmer over medium heat.
Simmer the mixture for 3 to 5 minutes to cook out some of the starch flavor from the flour.
Add 3/4-pound of the Monterey Jack cheese to the thickened half-and-half. When the cheese is melted, add the milk, the remaining 1 teaspoon salt, black pepper, and cayenne pepper. Stir in 5 ounces of the blue cheese and allow it to melt slightly. Place the macaroni in a large bowl and pour the cheese sauce over it. Stir well to coat the macaroni evenly. Pour it into the prepared baking dish and sprinkle the remaining 1/4-pound of grated Monterey Jack cheese over the top. Place the baking dish in the upper part of the oven. Bake the macaroni and cheese for 15 minutes. Sprinkle the remaining ounce of blue cheese on top. Return the dish to the oven and bake it for 15 minutes more, or until the top is golden brown and bubbly.
Remove the dish from the oven and allow the macaroni and cheese to rest 5 minutes before serving.