While the chicken is resting, heat a skillet over medium heat and melt 4 Tablespoons butter. While the butter melts, cook fettuccine pasta in a separate pot according to the package instructions until al dente (slightly underdone).
6 Tablespoons butter, 16 oz fettuccine noodles
Once the butter fully melts, add in minced garlic and cook 2-3 minutes, occasionally stirring.
1 Tablespoon minced garlic
Gradually and slowly add in heavy cream, stirring as you add it. This is super important: add it slowly while stirring so the cream doesn't curdle!
2 cups heavy cream
After adding all the cream, slowly sprinkle in parmesan cheese. Keep stirring while you are adding it.
½ cup parmesan cheese
Add in 2-3 slices of white American cheese and make sure to stir well.
2 slices white American cheese
Sprinkle alfredo with freshly cracked black pepper and stir to combine. Taste and adjust to your liking.
1 pinch freshly cracked pepper
Finally, add in your cooked pasta and mix everything fully together.
Top with additional parmesan cheese, pan-fried chicken slices and parsley to taste. Enjoy!