Cook pasta according to package directions and dump into colander to drain.
Add butter to pan.
Cook chicken on medium heat until no longer pink in center, or to 165 degrees. You can also poke chicken with a fork and if the juices run clear, it’s done.
Remove cooked chicken from pan and set aside.
Cut up onion and cook in pan on medium heat until tender and translucent.
Add garlic, herbs of choice, salt, pepper and grated parmesan cheese.