Build-Your-Own Mac ‘n Cheese
Preheat oven to 350°
Cook the pasta in lightly salted water, following package directions, about 12 minutes. Drain.
While pasta is cooking, melt butter in a medium-size, heavy-bottomed saucepan (not nonstick) over medium heat. Stir in flour until well blended; cook 1 minute. Whisk in 1/4 cup of the milk and cook, whisking continuously, until smooth. Whisk in remaining 1/4 cup milk and continue to cook, whisking until thickened and smooth, about 5 minutes. Remove from heat; stir in salt, pepper and nutmeg. Whisk in 1/2 cup of the cheese until smooth.
In a large bowl, mix together the pasta, cheese sauce and 1/4 cup of the remaining cheese. Stir in your choice of peas and ham, or bacon and tomato.
Pour into a baking dish coated with nonstick cooking spray. Scatter remaining 1/4 cup cheese evenly over the top.
Bake at 350° for 10 minutes or until bubbly. Remove from oven and let it cool for 10 minutes.
Garnish with crushed potato chips and/or chopped scallions.