Baked macaroni and cheese is considered a delicacy in most homes. I have never known anyone who did not like baked macaroni and cheese, no matter what their age.
Preheat oven to 375F. In a 5-quart pot, cook macaroni as package label directs; drain.
Meanwhile, melt butter in medium saucepan. Remove from heat. Stir in flour, salt, and pepper until smooth. Gradually stir in milk. Bring to boiling, stirring occasionally. Reduce heat, and simmer mixture 1 minute. Remove from heat.
Stir in 1 ½ cups cheese and the macaroni. Pour into 1 ½ quart, shallow casserole dish. Arrange tomato slices over top. Sprinkle remaining cheese over the top.
Bake 25 minnutes, or until cheese is golden brown.