Tuna Bean Casserole
["4 Tbsp. oleo", "4 Tbsp. flour", "2 tsp. salt", "1/2 tsp. pepper", "2 1/2 c. milk", "2 (7 oz.) cans tuna", "2 cans green beans", "2 Tbsp. parsley flakes", "2 Tbsp. mustard", "2 tsp. horseradish", "2 cans onion rings (if desired)"]
["Melt butter in skillet.", "Add flour, salt and pepper; blend well.", "Gradually add milk while stirring.", "Cook and stir over medium heat until thickened.", "Add remaining ingredients, except onion rings; mix well.", "Spoon into a greased 2-quart casserole dish.", "Add the onion rings, if desired, for the last 5 minutes of baking time.", "Bake at 350\u00b0 for 30 minutes."]
["oleo", "flour", "salt", "pepper", "milk", "tuna", "green beans", "parsley flakes", "mustard", "horseradish", "onion rings"]