Add the yoghurt, cold water, chilli, ginger, cilantro, cumin powder, black salt, regular salt, and chaat masala to the blender. 

Blend on medium speed until the mixture is smooth, frothy, and fully combined.

Take a moment to taste and adjust the salt or spices if necessary.

If you want a thinner texture, just add a splash of water and give it another quick blend for a few seconds.

Pour the blended chaas into a jug and pop it in the fridge for about 15 to 20 minutes.

Pour the chilled chaas into serving glasses. 

Garnish with fresh cilantro or mint for a burst of colour and aroma. 

Enjoy immediately for the best flavour and cooling effect.