Can anyone identify this fungi? It smells mushroomy when disturbed

It somehow got into our vege garden, possibly in compost or on vege plant seedlings. It grows in seemingly ever thinkening shields flat on the ground. It's also now got into the cracks of the concrete and retaining wall. We've tried to kill it with white vinegar, bleach, boiling water, fire (I'm not joking), spa pool chlorine and it keeps coming back.

I think knowing the enemy might allow some more killing progress, but so far LLM and google IDing is not working.

I'm not sure how I ask this question on iNaturalist, short of making an observation? If anyone has any experience with that too.