Combine all ingredients for the vinegar mixture, except lemon juice, in a saucepan. Place it over low heat to dissolve all the sugar and salt. Set aside to cool.
Peel and slice lotus root into 0.5 cm thick rings. Soak immediately in water (add 1 Tbsp vinegar) to prevent discolouration. Make flower cuts and drain before using.
Boil a pot of water and add the other Tbsp of vinegar