Slice onions and tomatoes and set aside
Now in a serving plate place onion slices and on the above place tomato slices or vice versa
Above these slices add mixture in large amount so that when you eat they have crunchy taste
Beat curd well but don't add salt as it releases water
Now on the top of the mixture add curd
Add all seasoning on the curd before serving that is salt, red chilly powder, chaat masala, garam masala etc
I just added salt and red chilly powder other ingrefients are optional
Add finely chopped coriander and serve
This is very famous tomato masala in our village machilipatnam