The handshake for which the shaker, sandwiches the shakee's hand between his/her two hands, the shaker tilts his/her head, and says something comforting.
John's dad just got hit by a car, so I gave him a comforting handsandwich.
is when you're stuck without anywhere to take a dump, so you dump in your hand. Comes from tradition in Nepal, where the word for "hand" is the same for the word for "toilet".
Dude, on the way to work today I took a Nepalese hand sandwich!