Initially, the chicken breasts are pounded to even thickness between plastic wrap. Subsequently, they're seasoned generously with salt, pepper, garlic powder, and Italian seasoning. Moreover, this ensures uniform cooking and maximum flavor penetration.

Meanwhile, olive oil is heated in a large skillet over medium-high heat. Then, the seasoned chicken is cooked for 6-7 minutes per side until golden brown and internal temperature reaches 165°F. Afterward, the chicken rests for 5 minutes before being sliced into strips.

Simultaneously, a large pot of salted water is brought to a rolling boil. Next, the fettuccine is cooked according to package directions until al dente. Importantly, ½ cup of pasta water is reserved before draining.

First, butter is melted in the same skillet used for chicken over medium heat. Then, minced garlic is sautéed for 30 seconds until fragrant. Gradually, heavy cream is whisked in and brought to a gentle simmer.

Consequently, the heat is reduced to low before Parmesan cheese is whisked in gradually. Furthermore, salt, white pepper, and nutmeg are added to enhance the flavor profile. Additionally, pasta water is incorporated if needed for proper consistency.

Finally, the drained pasta and sliced chicken are tossed with the alfredo sauce until well coated. Therefore, each strand of pasta becomes perfectly enrobed in creamy sauce. Ultimately, fresh parsley is sprinkled over the top before serving immediately.