Cook pasta according to package directions and dump into colander to drain.
Add bacon to pan. Cook on medium heat until crispy. Remove from pan and set aside on plate lined with a paper towel to drain.
In same pan with bacon fat, 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, milk, sour cream (or cream cheese or yogurt), salt, pepper and grated parmesan cheese. Stir and cook until thick and bubbly. Sauce can be thinned with pasta water, chicken stock, water or milk.