Take the yogurt and whisk it and then add the water to it. If you have buttermilk, then replace it with yogurt and water mix. Mix in the ginger-chilli paste, salt and green chillies, and mix it well.
Add the semolina and mix it nicely. Add a little water if you feel it is too thick. the batter should be not too thin and not too thick also.
Finally, let it sit for about an hour or so or if you have time on hand for 2 hours or so. Lot of times I have made them without letting it sit , but what makes the difference is if you let it sit, the yogurt helps in fermenting the batter and making it a little more flavorful. Remember, semolina will use up the water once you let it sit.
Whenever you are ready to prepare them, add in the chopped veggies and coriander leaves. Mix it well. At this point you might or might not feel like adding extra water. Do feel free to if you need to.
Now, take the equal amount of mustard seeds, cumin seeds and sesame seeds in a bowl and mix them.
Heat a skillet at medium high heat and add a small spoonful of oil about 1/2 tsp , add the cumin-mustard seeds-sesame seeds mix and be careful at this time the sesame seeds will go crazy and start popping up so quickly and might splatter on your face so please be careful and immediately pour in the batter on it top of the sesame mix and spread it a little like the way we make sweet pancakes. You can make them thin , if that's the way you like them or thick. it is totally up to you.
Let them cook on one side , you will be able to see a difference on the batter once they look cooked on one side and then flip it on the other side, add a little oil to moisten it. Let it cook for about a minute or so and then remove it .
Serve it hot off the griddle with some coriander/mint chutney.