Place eggs in a pot, cover with water, and boil over high heat for 8 minutes. Peel and finely chop hard-boiled eggs and stir in mayonnaise. If additional binding is needed, add sour cream. Season egg mixture well with salt and add white pepper. Dice and fold in chives. Alternatively you can use dill.

Arrange untoasted slices of bread on a plate. Generously spoon egg mixture on one slice, piling in the middle to start and then spreading evenly over bread. Top with a second slice. Add another layer of salad on the second slice, and then repeat until you have six layers of bread with filling stacked high. Carefully trim edges and cut stack in half diagonally. Repeat with six more slices of bread.

By stacking the assembly, you will create the most uniform and elegant egg salad triangles.