I don't like the Black circuits, they're poorly regulated, usually hysteretic, and know little or nothing about short circuit protection or current limiting.
I've got a few that are short on transistors,
This one being made for a high voltage output, but you can do whatever with the coil and what's after it. Like the Black circuits, this depends upon switch node voltage, so is supply sensitive (most importantly, too high voltage will cause it to run full-tilt as the 2N3906 discharges the capacitors via E-B avalanche), and the frequency will vary all over the place as supply is varied.
The 2N4401 can be replaced with a MOSFET for slightly better performance or capacity, but you're still limited by the 0.7V drop on the shunt resistor (2.2 ohm). It takes two additional transistors to reduce that.
Since you didn't specify if the components should be integrated or discrete, I would better suggest a SimpleSwitcher LM26xx or similar device. Those do around 5 components, and work very nicely; as long as you don't mind that there's a dirty IC on your circuit.
Tim