Schematic of my Mark 1 induction heater. Mark 2 is the same but with more caps and thicker wire.
The driver is not shown- I used the Dirty DRSSTC PLL driver with interrupter bypassed.

Mark 1 setup

A "Ghetto" H-bridge converts 30V DC at 7A (from a bench power supply) to RF at 120-250 kHz.
The whole bridge is built on top of a large 12,000uF @ 40V electrolytic.

Nut roast anyone?

The work coil caught fire and stunk out the whole kitchen.

See pictures of improved heater