Preheat the oven to 350°F. Grease a 9x13 inch baking dish.
In a large bowl, mix together the shredded chicken, cream of chicken soup, sour cream, garlic salt, and pepper.
Spread the chicken mixture evenly in the prepared baking dish.
In a separate bowl, combine the crushed Ritz crackers with melted butter.
Sprinkle the cracker mixture evenly over the top of the chicken mixture.
Bake for 25-30 minutes, or until the top is golden brown and the casserole is bubbly.
Let stand for 5 minutes before serving.
Notes
For extra flavor, add 1 cup of shredded cheddar cheese to the chicken mixture.You can use rotisserie chicken for convenience.If the topping browns too quickly, cover with foil for the last 10 minutes of baking. Refrigerate any leftovers in an airtight container for up to 5 days.