Hard boil the eggs: Cover with cold water, bring to a boil, remove from heat, and let sit for 12 minutes. Cool in ice bath, then peel and chop.

In a bowl, mix chopped eggs, bacon, jalapeño, mayo, and mustard.

Spread the mixture evenly onto 3 slices of bread. Top with the other 3 slices.

For mini sandwiches, trim crusts and cut each sandwich into quarters.