SANDWICHES
Spread mustard and mayo on each slice of bread.
Place the sliced ham and shredded cheese, about 2 tablespoons cheese on each sandwich, on the bread and close the sandwich.
Heat a large sauté pan over medium heat. Add some butter and grill the sandwiches, two at a time. Toast each side about 2 minutes until golden brown. Watch for burning the bread especially if you are using brioche.
Transfer the toasted sandwiches to a cookie sheet. You will continue to heat them in the oven later so don't worry if the cheese isn’t completely melted.
Pour the slightly cooled mornay over the tops of the sandwiches. Do not spread. The heat will cause the sauce to melt in the oven.
Place the toasted sandwiches topped with mornay sauce under the broiler for 2 minutes or so until the cheese sauce is bubbly.
While the sandwiches are in the oven, make your fried or poached egg. (You can omit the egg and serve a Croque Monsieur, but a fried egg makes this special.)
Pull the tray from the oven and serve the egg on top of the sandwich. Serve hot.
QUICK MORNAY SAUCE
Heat small saucepan on medium heat. Add the butter and let melt but not brown. Stir in the flour and whisk with a fork. Let cook while stirring about 1 min. Do not brown.
Add the milk and spices. Bring to a simmer and whisk with fork breaking up any lumps and stirring to prevent burning on the bottom.
Turn to medium low heat and let simmer 2 minutes. Whisk in cheese until totally smooth. Turn off heat.