I like fermenting cucumber sometimes. Slice it fine and add salt and a splash of live cider vinegar. You can eat it after a few hours and it will keep for days / weeks in the fridge. You can add soy and chilli - or anything else you fancy. It’s great on the side of meat.
I also make yoghurt and sour cream and sauerkraut.
Homemade sour cream is so much tastier thank shop bought - it’s actually tangy. I mix a big dollop of greek yoghurt into double cream, put it in a sealed tub then put it in my sous vide on 44 degrees. It converts in a few hours.
Carrot ribbons ferment quite well too.
A splash of live cider vinegar (with the mother in it) will always set things going.