Cucumber, Tomato and Onion Raita also called Kheera, Tamatar aur Pyaz ka Raita

2 cups plain yogurt
1 small red onion, finely minced
1 medium tomato - finely minced
1/2 cup finely chopped cucumber
2 green chillies, finely minced
1 tbs. chopped cilantro leaves minced
Salt to taste
1/2 tsp. coarsely ground roast cumin seeds.
1/4 tsp. coarsely ground roast cumin seeds for garnish
1/4 tsp. red chilli for garnish (optional)

To make, mix all ingredients together in a large bowl and transfer to a serving bowl. Garnish with a sprinkle of roast cumin and chopped red chilli. Serve chilled.

Source: http://www.indianfoodsco.com/Recipes/Raita/Raita.htm