Start with making the noodles by following the package instructions. Boil, cook to al dente and drain.
While the pasta is cooking you can prepare the sauce. Start with the roux. In a heavy saucepan over low/medium heat, melt the butter, then whisk in the flour, dry mustard powder, salt and pepper, and cook for about 3 minutes, whisking the entire time.
Slowly whisk in the milk and cream, until the butter/flour mixture has blended in well.
Simmer, while whisking, until the milk mixture thickens.
Once the mixture has thickened, stir in the cream cheese and goat cheese until melted.
Then stir in the shredded cheddar cheese until it is mixed thoroughly.
Pour the cheese mixture over the cooked noodles and toss.