Prep the ingredients per the instructions above.
Spread the mustard and mayo on one side of each slice of bread.
Build the sandwich: Lay a slice of cheese onto the bread. Place another slice of bread over top, then layer the ham and another slice of cheese. Top with a final slice of bread. Spread the butter on both outside slice of bread.
In a medium bowl, beat eggs with milk and salt.
Heat a skillet or griddle over medium heat. Add butter to coat the pan.
Carefully dip the sandwich into the egg mixture.
Brown the sandwich on all sides until golden brown and the cheese has melted.
Mix together the sparkling water and lemon. Serve over ice if desired.
Cut in half, serve with carrot sticks with ranch, and lemonade.