Heat olive oil in a large deep skillet or Dutch oven over medium-high heat.
Add the chicken pieces and cook for 5-6 minutes until browned and cooked through. Remove chicken from the pan and set aside.
In the same pan, add the minced garlic and sauté for 1 minute until fragrant.
Pour in the chicken broth and whole milk, then add the broken fettuccine pasta, salt, black pepper, and Italian seasoning. Stir to combine.
Bring the mixture to a boil, then reduce heat to medium-low. Cover and simmer for 10-12 minutes, stirring occasionally, until the pasta is cooked and most of the liquid is absorbed.
Return the cooked chicken to the pan and stir in the butter and grated Parmesan cheese until the cheese melts and the sauce is creamy.
Cook for an additional 2 minutes, stirring gently to combine all ingredients well.
Remove from heat and sprinkle with chopped fresh parsley before serving.