Pour cold water into a pot and gently place the eggs inside. It is important that the eggs are covered in water. On medium heat, cover the pot and bring the water to a boil. After 10 minutes, turn off the heat and let the eggs sit in the hot water.
Pour cold water and ice cubes into a bowl. Put the eggs inside the bowl immediately with the help of tongs to stop their cooking process. After 2-3 minutes, let them cool slightly. Remove the shells by tapping each on the countertop.
Chop the egg into bite-sized pieces after slicing it in the middle. It is not necessary to dice very finely. In a medium bowl, add the chopped eggs.
In another bowl, combine the chives, dill, Dijon mustard, salt, black pepper, crushed red pepper, mayonnaise, and crushed red pepper. Gently fold the eggs with a spatula to avoid mashing them.
Spread butter on the toasted bread. Put sliced tomato, lettuce, and egg salad mixture on top. Place another toasted piece of bread on top and enjoy!