Here is my version (about a 1/16 recipe from the original) that I learned in culinary school with my own variation.
Makes about 16 servings
110g unsalted butter
110g bread flour
44 fl. oz (5.5 cups) low sodium chicken broth, hot
16 fl. oz (2 cups) heavy cream or whole milk
225g cheese, Parmesan or mozzarella
pinch white pepper
pinch nutmeg, ground
1/2 tsp garlic powder or paste
1/2 tsp sea salt (keep in mind that Parmesan cheese is saltier than mozzarella, so adjust salt depending on which cheese you use)
Melt butter over low heat, then add flour. Fry for 5 minutes, stirring occasionally. Add white pepper, garlic, nutmeg and salt.
Quickly whisk in hot chiken broth then slowly bring to a boil.
Add warm cream or milk, return to a gentle simmer.
When the sauce is hot, whisk in cheese until completely melted and sauce is thick.
Serve within 20-30 minutes over pasta or rice.
2010 Chef Andrew Rocuant
I recommend serving over spaghetti or fetticcini. Also pairs well with chicken or shrimp and or mushrooms with a fresh green salad and crusty garlic bread on the side.