- Use bone-in, skin-on chicken breasts. This will help keep the chicken moist as it cooks.u003cbr/u003e- Don't overcook the chicken. Cook it until it's just done, or even slightly underdone.u003cbr/u003e- Add a layer of moisture to the casserole. This can be achieved by adding some broth or water to the bottom of the dish before adding the rest of the ingredients.