Make enough waffle batter for 4 round waffles, per your package instructions. Mix the batter with your cheese, chives and salt/black pepper per taste.
Make your waffles as you normally would, and set aside to cool.
Egg Salad
In a bowl, mix together your eggs, mustard, mayonnaise, cherry tomatoes, red onion, celery and chives. Add salt/black pepper per taste.
To Assemble
Use kitchen scissors or a knife to cut your waffles into 4 triangular pieces each. Evenly divide the waffle pieces and spread on the egg salad to half of them. Close up each waffle & your sandwich is ready to serve!