For an extra layer of flavor, add a pinch of smoked paprika or a dash of Worcestershire sauce to the cheese sauce. If you prefer a smoother sauce, you can use an immersion blender to blend the sauce after the cheese has melted. Adjust the amount of mustard and seasoning to your personal preference. For a richer flavor, use a combination of Cheddar and Gruyere cheese. Garnish with chopped parsley for a fresh, vibrant finish.