Baked Ham Mac and Cheese

3 Tablespoons butter or margarine
2 Tablespoons flour
4 cups milk
1 Tablespoon Dijon mustard
¼ teaspoon salt
1/8 teaspoon cayenne pepper
1 onion, chopped
¼ pound mushrooms, sliced
½ pound smoked cooked ham, cut into 1/4inch pieces
2 ½ cups grated cheddar cheese
¾ pound elbow macaroni
½ cup Parmesan cheese

Heat water for the pasta in a large saucepan. Heat the oven to 400 degrees.

Heat 2 tablespoons of the butter in a 2-quart saucepan over low heat until foaming. Add the flour and cook, stirring for 2 minutes. Gradually stir in the milk and continue to stir until the mixture is smooth. Stir in the mustard, salt, and cayenne.

Heat the remaining butter in a large skillet over medium heat. Add the onions and cook, stirring, for 4 to 5 minutes until softened. Add the mushrooms and ham and cook for an additional 10 to 12 minutes until he mushrooms are tender and the excess liquid has evaporated.

Gradually add the cheddar cheese to the white sauce, stirring after each addition, until melted. Add the mushroom mixture and stir well to combine.

Meanwhile, cook the pasta for 12 to 15 minutes until tender. Drain well in a colander.

Spoon half the macaroni into a buttered, 3-quart baking dish. Add half the sauce and s tir gently to combine. To with the remaining macaroni and pour the remaining sauce over it. Sprinkle with the Parmesan cheese and bake for 20 minutes.