Preheat oven at 180°C.
Heat 1 tbsp oil in a non-stick pan. Add 1 tsp carom seeds, turmeric powder, red chilli powder and garam masala powder. Mix well, add little water and sauté for a few minutes.
Add gren gram, mix and cook. Add salt, dried mango powder and chaat masala, mix well and cook till the gram is fully cooked.
Chop coriander and mint sprigs and add in the pan. Mix well and cook for 30 seconds. Switch off heat and cool the mixture to room temperature.
Combine refined flour, 2 tbsps oil, remaining carom seeds and salt in a bowl. Add sufficient water and knead into a stiff dough. Set aside for 15 minutes.
Divide dough into equal portions and shape them into balls. Spread balls into round discs, place a portion of cooked gram mixture, bring the edges together and seal into a round. Dust the kachoris with little flour and place them on a silicon sheet spread on a baking tray. Pat them a bit and brush with oil.
Put tray in the preheated oven and bake for 8-10 minutes.
Garnish with coriander sprigs and serve hot with soonth chutney.