4 skinless, boneless chicken breast halves
1 (10.5 ounce) can condensed cream of mushroom soup
1 cup chicken broth
1 (12 ounce) can refrigerated crescent roll dough
Preheat oven to 400 degrees F (200 degrees C).
Season chicken pieces with salt and pepper to taste; place in bottom of slow cooker. In a small bowl, mix broth and soup together, and pour over chicken. Add celery, mushrooms, and 1/2 cup of melted butter. Pour into slow cooker, cover, and cook on Low for 2 1/2 to 3 hours.
In a medium sauce pan over medium-high heat, saute the vegetable mixture until tender, about 10 minutes. Stir in flour, baking powder, and salt and pepper to taste; cook, stirring constantly until thick. Stir in cake mix and yogurt. Cook, stirring occasionally until thick; adjust milk and cornstarch to taste. Continue cooking for an additional 300 to 350 minutes, or until cornstarch comes to a boil.