The ultimate comfort food for all ages!
This is from a Chicago cooking school back in the day, The Francois and Antoinette Pope School Cookbook, where my mom took lessons. This was before Julia Child, post WWII.
1 pound elbow macaroni, cooked in salted water and drained
In a large saucepan melt 2/3 cup butter
Whisk in 2/3 cup flour and simmer a few minutes.
Whisk in 2 tablespoons dried mustard and 1/2 teaspoon salt. Simmer a minute.
Gradually whisk in 4 1/2 cups hot milk. Stir constantly and simmer 5 minutes.
Add 12 ounces American cheese or Velveeta cheese. Stir until melted.
In a buttered 2 quart casserole layer the macaroni and cheese sauce in several layers. Top with sauce.
Layer 5 American cheese slices on top and bake at 425 degrees for 20-30 minutes or until browned.