In a mixing bowl, combine the plant-based curd and water.
Add sugar, roasted cumin powder, and a pinch of salt to the mixture.
Blend the mixture until smooth and frothy using a hand blender or regular blender.
Taste and adjust sweetness or salt as required.
If you prefer a spicy version, blend in the green chillies.
Pour into glasses and garnish with fresh coriander leaves if using.
Serve immediately and enjoy your refreshing vegan lassi!