3 tbsp. butter
2 tbsp. minced onion
3 tbsp. flour
1 tsp. salt
2 c. milk
1 can (7 oz.) tuna, drained
4 c. thinly sliced potatoes

Heat butter in saucepan and saute onion about 5 minutes. Blend in flour and salt gradually, stir in milk and stir over medium heat until thickened. Stir in tuna. Put potatoes in greased 2 quart casserole dish and stir in tuna mixture. Cover and bake at 350 degrees for 1 hour. Uncover 30 minutes or until potatoes are tender.