Raita has many variants. It can be made with fruits, vegetables, mint, boondi (fried gram flour droplets). It can be sweet, savory, salty, spicy, etc. The most popular one is cucumber, tomato and onion raita. It always enhances the food it is served with.
For the tomato, I like to peel the skin and remove the seeds. To do that, first get some water boiling and dip the tomato in to the boiling water for two minutes. Then take it out and dip in ice cold water for 2-3 minutes. Now you can take a knife and peel the skin. It will come off very easily. Also, remove the seeds before adding them to the yogurt.
In a big bowl take the yogurt and whisk it to arrive at a smooth consistency. Now mix all the vegetables, chili, and cumin powder, into the yogurt. Sprinkle the cilantro. It is ready. Add the salt just before you serve. Mixing salt too early makes the raita watery.
Enjoy with any food!