Sprinkle one tablespoon of lemon juice over the apple slices to prevent discolouration. Peel the oranges and separate the segments.
Remove the seeds and cut each segment in half. Combine the apples, oranges, green grapes, black grapes, green capsicum, cucumber, tomatoes, spring onions and green chillies in a large bowl.
Add salt, chaat masala and mix. Add olive oil and mix. Serve chilled.