In a bowl, whisk eggs and egg whites together. Finely chop spinach and add desired amount to egg mixture. Dice ham into tiny pieces. Grate the cheese.
Cut one of the pastry sheets in half lengthwise. Cut each of those halves into thirds for a total of 6 pieces. Press into muffin tin. Fill the puff pastry with the egg mixture. Sprinkle each with cheese and ham. Season with salt and pepper.
Bake for 10-15 minutes or until the egg and crust are cooked through. Allow to cool. If preparing for a school lunch, make ahead of time and refrigerate overnight.