Place 1/2 of roasted red bell pepper into food processor and pulse until small pieces of pepper are formed. If watery, strain as necessary. Set aside.
Cook fettuccine, according to package directions and set aside.
Cut chicken breast into thin, 1/2 slices and cook in small skillet over medium-high heart. Set aside.
Heat olive oil in a medium-sized sauce pan over medium heat. Add garlic and cook, stirring, until golden brown, about 1 minute.
Sprinkle in flour and whisk to incorporate and cook for 1 additional minute.
Slowly whisk in chicken broth, butter, then milk. Whisk in Greek yogurt, garlic salt, salt and pepper, then turn the heat down to low. Let the sauce simmer until thickened, about 2-3 minutes.
Turn the heat to low then stir in Sargento Chef Blends Shredded 6 Cheese Italian and roasted red pepper. Toss sauce with chicken and pasta. Serve with additional cheese and chopped Italian parsley.