Add the beer to a saucepan over medium heat. Bring to a low simmer, do not boil.
In a medium-sized bowl toss together both types of cheese and the cornstarch.
A small handful at a time adds the cheese to the beer, stirring until the cheese is melted before adding more.
Once all the cheese has been melted, stir in the Dijon, Worcestershire, salt, and pepper until well combined. Add the sauce to a warm fondue pot.
Serve with bread, vegetables, and meat.
Notes
*Note: Use a lighter-colored beer for best results. For a stronger beer flavor use a hoppier beer like an IPA or an American pale ale. For a milder beer flavor use a wheat beer, pale lager, Kolsch, or pilsner.