• Heat olive oil in a large skillet over medium-high heat. If using whole chicken breasts, cook for approximately 5 to 7 minutes per side, depending on size and thickness. Season with salt and pepper, adding minced garlic during the last few minutes of cooking. If using diced chicken, add to the skillet, sprinkle with salt, pepper, and minced garlic, and cook until golden brown, about 6-8 minutes. Once cooked, remove chicken from the skillet and set the heat to low.
• Meanwhile, prepare the fettuccine according to package directions.

For the Sauce:

• In the same skillet, melt butter over low heat. Stir in flour, increase heat to medium, and whisk until the mixture turns a light golden color, about 2 minutes.
• Gradually whisk in half-and-half, followed by granulated garlic and salt.
• Bring the mixture to a simmer, whisking continuously. Once it begins to simmer, stir in grated parmesan cheese until melted.
• Return cooked chicken to the sauce, let simmer for 2 more minutes. If using whole chicken breasts, slice them before returning to the sauce. The sauce will thicken upon simmering and standing. For a thinner sauce, add extra half-and-half or chicken broth as desired, or more parmesan cheese for a thicker consistency.
• Serve the chicken and sauce over cooked pasta. Garnish with additional grated parmesan cheese and fresh parsley, if desired.