Lassi (pronounced [ləsiː]) is a popular traditional dahi (yogurt)-based drink that originated in India. Lassi is a blend of yoghurt, water, spices and sometimes fruit. Namkeen (salty) lassi is similar to doogh, while sweet and mango lassis are like milkshakes

Source: https://en.wikipedia.org/wiki/Lassi

Some Recipes on Lassi:

How To Make Lassi Recipe | 1 Minute Series | Indian Cooking Recipes 

https://www.youtube.com/watch?v=gugVM1YXqQo

How to Make Lassi

https://www.youtube.com/watch?v=tPaXwLSScEE

Punjabi Sweet Lassi | Sweet Yogurt Drink | Refreshing Summer Cooler Recipe

https://www.youtube.com/watch?v=tziQpzMX8Uk