Soak the bread slices in one cup of water for half a minute, squeeze to remove excess water and set aside.
Place the grated potatoes, half tablespoon garlic paste, half tablespoon ginger paste, green chillies, bread, salt, green peas, one and a half teaspoons red chilli powder, one teaspoon coriander powder, one teaspoon roasted cumin powder, quarter teaspoon turmeric powder, mint leaves and coriander leaves in a deep bowl.
Mix well and set aside for one hour, preferably in a refrigerator. Divide the mixture into twelve equal portions. Shape each portion into a cutlet.
Heat sufficient oil in a deep kadai. Mix cornflour in water to make a thin batter. Dip the cutlets in cornflour mixture and deep-fry for two to three minutes on each side. Drain on absorbent paper.
To make the gravy, heat two tablespoons oil in a pan and sauté onions till lightly browned. Add the remaining garlic paste and ginger paste and half cup of water and sauté for a minute.
Add the remaining turmeric powder, the remaining coriander powder, the remaining red chilli power and chopped tomatoes and mix well and cook till the tomatoes turn pulpy. Add tomato puree, mix and bring the gravy to a boil. Add another half a cup of water, salt, sugar, the remaining roasted cumin powder and mix well.
Cover and cook for four to five minutes. Add vinegar, mix and cook for two more minutes. Place the cutlets on a serving platter, pour the tomato gravy over
Garnish with the potato wafers and serve hot.