1. Put mashed garlic cloves in the cheese cloth and tie up the neck then add the sachet in a small sauce pot with 1 cup of milk and bring slowly to a boil, then simmer for 10 minutes.
2. Strain the aromatic milk, squeezing the garlic sachet to extract all juice. Set aside to cool.
3. In heavy saucepan over low heat, melt butter. Stir in flour with a wire whisk. Cook over low heat for three minutes, stirring constantly. Do not allow the mixture to brown. Gradually stir in aromatic milk, whisking constantly. Cook over low heat for 3-5 more minutes until sauce begins to thicken. Remove from heat.
4. Put the sauce in a large serving bowl, warmed; stirr in egg yolk, Swiss cheese and season to taste with fine sea salt and white pepper. Whisk thoroughly with a small whisk until well combined.
5. Meanwhile, in a large pot, bring 1 1/2 gallons (12 pt) of water to a rolling boil.
6. Add the 4 tablespoons coarse sea salt, then add the pasta and cook until al dente.
7. Drain well in a colander.
8. Add cooked pasta to the sauce in the serving bowl, combine, then add butter curls; mix well to gently combine all ingredients until butter is melted and serve immediately.

Suggested shape of pasta to use with this sauce:
Spaghetti, Linguine, Orecchiette, Caserecce, Elicoidali, Radiatori or Wheel