Macaroni and Cheese

4 cups dried macaroni
1 whole egg beaten
1/4 cups butter
1/4 all purpose flour
2-1/2 cups whole milk
2 teaspoons dry mustard
1 pound cheese grated
1/2 teaspoons salt
1/2 teaspoons seasoned salt
1/2 teaspoons ground black pepper
optional spices cayenne pepper paprika, thyme

Cook macaroni until very firm. macaroni should be to firm to eat out of the pot.drain.
In a small bowl beat egg.
In a large pot melt butter and sprinkle in flour. Whisk together over medium to low heat. Cook mixture for five minuets whisking constantly. Don't let it burn.
pour in milk add mustard and whisk till smooth. Cook for five minuets until very thick.Reduce heat to low.  Take 1/4 cup of the sauce and slowly pour into beaten egg whisking constantly to keep egg from cooking. Whisk together until smooth.
Pour egg mixture into sauce whisking constantly. stir until smooth.
add in cheese and stir to melt.
Add salt and pepper. taste sauce and add more salt and seasoned salt as needed. do not under salt.
Pour in drained cooked macaroni and stir to combine.
Serve immediately,or pour into a buttered baking dish, top with extra cheese, and bake for 20 to 25 minuets or until bubbly and golden on top.