Into a large bowl, add eggs, milk, and seasoned salt along with some salt and pepper. Whisk together until frothy.
Spray a 9x13 pan with cooking spray and pour the eggs mixture.
Bake at 400 degrees for 15 minutes, or until the eggs puff up fully cooked. You can test by seeing if a knife inserted in the center comes out with no wet egg on it.
Allow them to cool for about 5 minutes, then cut them into 12 rectangles the same size as your croissants.
Add a slice of egg to each croissant along with some ham and cheese.
Spray a 9x13 pan with cooking spray and place the sandwiches inside.
Cover tightly with tin foil. Pop it in the fridge until you are ready to serve.
To serve, preheat your oven to 400 degrees. Bake for 15 minutes or until the sandwiches have heated through and the cheese is melted. Makes 12 sandwiches.