Preheat oven to 350, cook pasta according to package directions.
Meanwhile, melt butter over low heat in large saucepan.
Add in flour, salt, pepper and garlic, and cook stirring constantly until smooth.
Remove from heat and slowly add in chicken broth and half & half.
Return to heat and bring to boiling.
Boil for a minute, stirring constantly.
Add in pasta and chicken, and top with Parmesan cheese.
Bake for 30 minutes at 350, until bubbling.
Enjoy!