Poach chicken in a large pot of simmering water. Cook until no longer pink in center, about 12 minutes. Remove and set aside. Bring chicken cooking water to a boil and cook pasta in it.

Cut chicken into small pieces, and mix with noodles.

In a separate bowl, mix together soups and sour cream. Season with salt and pepper. Gently stir together soup mixture with chicken mixture. Place in a 2 quart baking dish.

Melt butter in a saucepan, and remove from heat. Stir in crumbled crackers. Top casserole with the buttery crackers.

Bake at 350°F for about 30 minutes, until heated through and browned on top.