Soak whole wheat in three to four cups of water for ten to twelve hours. Drain and pressure-cook along with two to three cups of water and salt till done.
Drain and keep aside. Cut tomatoes into half-inch sized cubes. Finely chop green chillies. In a large bowl combine cooked wheat, roasted peanuts, tomatoes, cucumbers, coriander leaves, green chillies, lemon juice and chaat masala.
Toss to mix well. Serve topped with scraped coconut.