Preheat oven to 350°C

Make topping by tossing Panko with the melted butter in a medium bowl. Mix in the cheese. Set aside.

Cook pasta according to directions. Drain and cover.

While pasta is cooking, melt butter in a large saucepan and blend in flour, salt, and pepper. Cook until the mixture is bubbly, then gradually add the milk, stirring while adding. Stir in the Dijon.

Over medium hear, cook and stir until the sauce boils, then simmer for 1 minute, stirring constantly.

Add the pasta to the cheese mixture and toss lightly to cost. Pour into a 9 inch square baking dish. Then sprinkle with topping. Bake for 20-25 minutes, or until the cheese is bubbly and the topping is lightly golden.