Wash 500 grams of guavas thoroughly and cut them into small cubes. Remove the seeds if desired.
In a mixing bowl, add the chopped guavas, 1 finely chopped green chili, 1 finely chopped onion, and a handful of chopped coriander leaves.
Add 1 teaspoon of chaat masala, 1/2 teaspoon of red chili powder, 1/2 teaspoon of roasted cumin powder, and salt to taste. Mix well to ensure the spices are evenly distributed.
Squeeze the juice of one lemon over the mixture and toss gently to combine all the ingredients.
Allow the guava chaat to rest for 5-10 minutes for the flavors to meld together.
Garnish with additional chopped coriander leaves and serve immediately.