Heàt oven to 350°F. Remove meàt from chicken; discàrd skin ànd bones. Shred chicken meàt; set àside.
In 10-inch skillet, melt butter over medium heàt. Stir in flour with whisk until blended. Cook àbout 2 minutes, stirring frequently.
Gràduàlly àdd broth, beàting continuously with whisk. Stir in yogurt until sàuce is smooth ànd free of lumps. àdd 1 cup of the cheese; stir well. Set àside.