Creamed Turkey

3 T butter
3/4 C sliced mushrooms
3 T flour
1 1/2 C milk
1/2 C hot chicken or turkey stock
1 small 2 oz jar diced pimiento
4 C diced cooked turkey or chicken
salt
celery salt

Melt butter over medium-low heat. Sauté mushrooms. Add flour; stir until smooth. Slowly pour on milk and stock, stirring constantly, until thickened and bubbly. Add pimiento, turkey or chicken, salt, and celery salt. Cook until heated through, but not boiling.