I don't know where my mother got this recipe but it is the touch of nutmeg and the walnuts that make it shine. I often leave the nuts out so don't let those stop you in making this. It was one of our favorites growing up and my kids love it too.
2 tablespoons shortening
2 tablespoons flour
1 teaspoon dry mustard
1/8 teaspoon nutmeg
1 teaspoon Worcestershire
2 dashes Tabasco
2 cups milk
Make a white sauce. Stir over low heat until thickened. (For instructions on making a white sauce, take a look at the recipe for Pasta Baked with Bechamel and Parmigiano ... bechamel is Italian for white sauce.)
1/4 cup grated Parmesan
12 ounces tuna
Sautéed sliced mushrooms (optional)
1/3 cup broken walnuts (optional)
Add cheese, stir until melted. Add remaining and heat to serving temperature. Serve over rice or noodles.