Place all ingredients except the yogurt into a grinder or blender.
Add a tablespoon of water, and blend until you achieve a smooth paste like consistency. If needed, you can add a little more water.
In a separate bowl, transfer the yogurt. Whisk with a fork to get rid of any lumps.
Pour over the prepared mint sauce, and mix well until combined.
Chill in the refrigerator until ready to serve.
Notes
Cumin seeds: Some recipes call for dry roasting the cumin seeds before adding to the blender with the rest of the ingredients. I think it doesn't make much of a difference in terms of flavor, so skip this step. You can also use 1/4 teaspoon of cumin powder in place of cumin seeds.
Cilantro: Also known as coriander, it adds an additional flavor to the raita.
Mint Leaves: Only use the leaves, and avoid adding any of the stems as this can add a bitter aftertaste.
Yogurt: Traditionally plain yogurt is used, however it should be fine to use plain greek yogurt as well.
Storage Instructions: You can store the raita in the fridge for 2-3 days. If you want you can make a bigger batch of the mint base, and freeze it into ice cubes. Take out an ice cube or two, thaw it and mix with yogurt for a quick raita.