Mix together yogurt, garlic paste, ginger paste, red chilli powder, garam masala powder and salt. Marinate mutton mince in this marinade for about thirty to forty minutes.
Heat oil in a pan. Add marinated mince and cook on medium heat till the mince is cooked and dry. Divide into eight equal portions. In another bowl mix together whole-wheat flour, yogurt and salt. Add sufficient water to knead into a soft dough. Allow it to rest for eight to ten minutes. Divide dough into eight equal portions.
Roll out each portion into rotis of seven inches diameter.
Heat a tawa, place a roti on it and roast till brown specks appear on both sides. Set aside. Spread a teaspoon of coriander and mint chutney on each roti, dribble some chilli sauce and tomato sauce.
Place one portion of mince, some onion rings and sprinkle lemon juice and chaat masala.
Roll up the rotis and serve the rolls immediately.