Last year I gave Tim the gift of a course on making biochar https://thisnzlife.co.nz/why-your-soil-needs-biochar-plus-two-ways-to-make-it/
..... he loves fire and wood, and I figured the garden would be the beneficiary of anything that came of it.
The knowledge languished in him for a while - the sticking point being finding or creating enough of the right sized of peices of wood to burn. Then we cleared this years firewood pile, stacking the last of it up in the shed by the house ... and what lay at the bottom was a large layer of the right sized wood!
He spent a happy Saturday afternoon in pyromaniac bliss, and yesterday dug out 3 buckets of biochar for me to figure out how to activate. Looks like my next mission is building a proper compost pile.