The best spinach we've ever grown was a handful of seeds just tossed in an old parsley bed and raked in. No forking, no digging, no weeding, no hoeing, no mulch, no cover, no raised bed, no nothing. Bare soil. 30 cm of snow covered it until mid March and then, in April, there were those massive spinach plants.
That was 5-6 years ago. Since then we've tried all the "pampering" methods, row covers, hoop tunnels, deep mulch, spring planting, autumn planting... And no, the results were miserable compared to what we got using the STUN method!
I had a similar experience. The best spinach I had was grown by just throwing the seed on top of about an inch of compost and raking in, in the fall. It was the first compost I had ever made actually. The spinach was just amazing. I still haven’t been able to grow it so flavorful and sweet.