In a mixing bowl, add the yogurt and whisk it well.
Add the roasted cumin, sugar, dried mint, salt and red chili powder if using and mix everything well.
Add the chopped coriander leaves and mix well again.
Now add the water to desired consistency and give this a good mix.
I usually add the boondi at this stage and mix well with the seasoned yogurt.
If you prefer to soak the boondi, you may do that in 2 cups of warm water for 15 minutes. Once soft, drain the water and transfer the soft boondi to the seasoned yogurt.
Refrigerate the boondi raita for minimun 30 minutes before serving.
You may garnish with some roasted cumin and red chili powder when you are ready to serve.