If you've accidentally left your bagels out to get stale and dry up, this toasting method will make them just as scrumptious as before. Photo by Ezra Wolfe.
Obviously, the best way to avoid a dry and stale bagel is with proper storage in an airtight container or it's own bag, but accidents happen. If your bagels are starting to feel like they'd crack your kitchen tile if you dropped them, J. Kenji López-Alt at Serious Eats suggests you give them a warm bath before toasting. Dunk the rock-hard bagel in a bowl of hot water, then toast it whole in your toaster oven or in your regular oven at 190C for four to five minutes.
The Right Way to Toast a Bagel [Serious Eats]