Skillet Macaroni and Cheese with Tomatoes and Herbs

This is a very good Macaroni and Cheese,
made in a skillet on top of the stove.
Where you can add any fresh vegetables you wish
to the macaroni to blend in with the cheese.

Ingredients:
4 tablespoons unsalted butter, plus extra for the skillet
1 large yellow onion, cut in 1/8-inch dice
1 tablespoon minced garlic
3 tablespoons all-purpose flour
4 cups whole milk
1 teaspoon paprika
1/2 teaspoon ground nutmeg
2 teaspoons kosher salt
1 teaspoon freshly ground black pepper
3/4 cup grated extra-sharp Cheddar cheese
3/4 cup grated Wisconsin Asiago cheese
3/4 cup grated dry Jack cheese (Parmesan can be substituted)
1 pound elbow macaroni, cooked and drained
2 plum tomatoes, sliced
1/2 cup fresh breadcrumbs
1 tablespoon chopped parsley
1 tablespoon chopped thyme
1 tablespoon chopped chives

Directions:
Preheat the oven to 400 degrees F.
Melt the butter in a large pot over medium heat.
Add the onions and garlic, and cook until
they are softened, about 2 minutes.
Whisk in the flour and cook, stirring constantly,
until the mixture turns light brown, about 3 minutes.
Gradually whisk in the milk.
Add the paprika, nutmeg, salt, and pepper.
Reduce the heat to low and cook, stirring,
until the sauce is thickened, about 5 minutes.
Add the cheeses, and stir until they are melted.
Add the macaroni, and stir until the
noodles are thoroughly coated. Remove from the heat.
Butter two 6-inch cast-iron skillets or one 12-inch skillet.
Transfer the macaroni mixture into the skillets.
Top with the sliced tomatoes. Sprinkle bread crumbs on top.
Bake until the cheese is bubbling and golden brown, about 30 minutes. Garnish with the chopped herbs.