I made vareniki again, savoury this time. I used a filling of onion, turnip stalks, beetroot and cooked potato sweated in dripping, and boiled them this time instead of steaming them, then finished them under the grill with a sprinking of cheese.
I couldn't work out what recipe I could have used last time that involved bicarb, so just used plain sourdough with a slosh of oil and a pinch of bicarbonate of soda added after the first rising. They definitely did swell in the cooking; I used a round cutter and put them into the boiling water in batches, and the finished ones came out much bigger than the ones that had newly gone in!