Single Gate LED Flasher

Hi,
I have another of my knucklehead questions. Is it possible to make a controllable, (on-off), single-NAND-gate LED flasher? I can do it easily with two gates as an oscillator or RS flip-flop, but I've never seen it done with only one gate. Thanks.

With schmitt-trigger NAND can do this. When the switch is open=run.