Coat washed and dried beetroot with oil, wrap it with aluminium foil and bake it in the oven for 45 minutes or until cooked through.
Once cooked, cool and remove the skin.
Grate the beetroot and add to the buttermilk.
Add green chilly, cumin powder, black pepper, black salt and handful of coriander leaves.
Leave in the refrigerator to chill and for the flavours to infuse for atleast 45 minutes.
Strain before serving.
Transfer to serving glasses and top with ice cubes if required.