how to boil water (and eggs)
After years of guessing (or calling home) every time I attempted to hard boil eggs - something I only did sporadically, admittedly - I stumbled on a pretty idiotproof method to get it right every time, so I thought I'd share. Just put your eggs in a single layer in a pot, cover with a few centimeters of water, and set the pot to boiling on high heat. About a minute after the water first starts to boil, turn off the heat, put the lid on the pot, and walk away for 12-15 minutes. Put eggs in ice water (either scoop them out into a prepared bath, or start running cold water over the pot as you drain it and then add ice) and let them cool. I've not over- or under-cooked them since!