Tuna Noodle Cassarole in Gluten-Free Recipes & Cooking Tips Posted February 28, 2007 · Report to Admin It's simple if you know how to make a white sauce! You can use corn starch or rice flour. 3-4 tablespoons of butter or margarin 2-2 1/2 tablespoons of flour or corn starch pinch of salt and pinch of pepper 2 cups of milk Melt butter in a sauce pan on med-low heat, once melted stir in flour, salt and pepper. Simmer lightly until the mixture is a light golden color (about 1 to 1 1/2 minutes) stiring constantly, SLOWLY add milk stirring constantly. Bring to a bowl continuing to stir, boil for about an minute. I use: about 2-3 cups of pasta, cooked, (3 if they are egg noodles) two cans of tuna (in water) drained, 1 cup of frozen veggies combine in a casserole dish, then pour in white sauce mix gently. bake at 375 for 10mins or until bubbling. makes 4-6 servings I hope this helps you, my boyfriend mother is a huge fan!