Preheat oven to 350 degrees.
Boil chicken until done. (I like to boil mine with an onion, carrot, a couple of celery sticks, salt & pepper, and chicken bouillon to make a flavorful broth)
Let chicken cool slightly and cut into bite size pieces.
Place cubed chicken in a 9X13 casserole dish.
Stir together the condensed soup, yogurt, and optional ingredients if using.
Pour over the chicken.
In a separate bowl, stir together the crushed crackers, melted butter and chicken broth.
Sprinkle over the chicken and sauce.
Bake for 30 minutes in the preheated oven, until topping is lightly toasted and sauce is bubbling.