Wash beetroot bulbs and place them in a pot of cold water. Bring to boil and cook until beetroot is just tender. Take it off the heat and let it cool completely.
Peel off the skin and slice the beetroot into thin slices.
Place the sliced beetroot in a bowl, add in the slit green chilli, vinegar, black pepper and salt. Gently mix and coat the beetroot.
Keep it in the fridge to cool for 20 minutes before serving.