Preheat the oven to 350°F/180°C, and spray a 9×13 inch pan with non stick spray. In salted water cook egg noodles until al dente according to package directions, drain and set aside.
As the pasta is being cooked, make the cheese sauce. Melt butter in a saucepan, add garlic and cook for 30 seconds, then add the flour and stir and cook for 1 more minute.
Slowly add the milk while whisking, then add the dijon mustard and pepper and whisk again. Add the parmesan and swiss cheese, and whisk until melted and smooth.
Make the topping, in a small bowl combine breadcrumbs with parmesan and butter. Top the casserole filling with the topping, and bake for 25-30 minutes.