Place fettuccine in a pot of boiling water that’s been seasoned generously with salt. Cook until desired doneness.
In a large pan, add heavy whipping cream and unsalted butter set to medium heat. Constantly stir the pan until all the butter has melted.
Increase the heat slightly and bring to a gentle simmer. Simmer, stirring occasionally, for 3-4 minutes or until lightly thickened.
Cut off the heat and add in parmigiano reggiano, chopped thyme, and finely chopped garlic. Vigorously stir together until thoroughly combined. Season to taste with salt and pepper.
Reserve ¾ cup of pasta water. Drain the pasta.
Add pasta to the alfredo sauce. Toss and using pasta water as needed to fully emulsify.
Place in a bowl. Top with grated parmigiano reggiano and a crack of black peppercorn before serving.