Heat oil in a non-stick pan. Slice onion and add. Chop green capsicum. Add tomatoes, turmeric powder and ginger-garlic paste to the pan. Mix well and sauté for 2-3 minutes.
Add tomato puree. Mix well and cook on high heat for a minute. Add capsicum, cottage cheese, salt, red chili powder and all spice powder. Mix well and cook till done.
Place a chapatti on a worktop. Mix mint-coriander chutney and yogurt and spread a spoonful of yogurt-chutney evenly on it. Place a spoonful of the vegetable filling on one side of the chapatti. Sprinkle a few fresh mint leaves, onion rings and chaat masala on top. Roll the chapatti tightly. Make other rolls similarly.
Cut into halves and serve immediately