Cook the chicken breasts and shred them (I always make my chicken ahead of time so it's easy to throw together at dinner time).
Preheat the oven preheated to 350-degrees.
Add the shredded chicken breasts to a large bowl.
Next, add the cream of chicken soup, sour cream, minced onion, garlic salt, salt, and pepper. Mix well.
Place the chicken mixture in a greased casserole dish.
Crush the Ritz Crackers in a large Ziplock bag and pour over the chicken.
Melt the butter and pour over the crackers.
Bake for 20 to 30 minutes, or until the crackers are golden brown and the chicken is hot.