For Rice Layer: Soak rice in cold water for at least 30 minutes. Add all the other ingredients listed along with 2 cups of water in a microwave safe bowl for 8 minutes. Rice should be 75-80% cooked and all the water should be absorbed.
For the Chana Masala Layer: Heat 2tbsp oil in a pan, add the onions and green chilies; cook until onions are lightly browned. Add ginger-garlic paste and cook for 1 minute.
Next add tomato and cook until mushy. Add ground coriander, cumin, red chili powder and salt. Cook for 1-2 minutes.
Add the whisked yogurt and chopped herbs. Cook for 2 more minutes. Remove from heat and set aside until ready to use.
Make caramelized onions: Heat 1tbsp oil in a pan and the sliced onions. Cook on medium flame stirring frequently until the onions turn golden and start to caramelize, about 20-25 minutes.
Assemble the Biryani: In a heavy bottomed wide pan, add 1/3rd of the rice, followed by ½ of the chana masala and ½ of the caramelized onions. Top this with 1/3rd of the rice and remaining chana masala. Finally add the remaining 1/3rd of the rice and the caramelized onions. Sprinkle some chopped mint and cilantro. Cover tightly with the lid and cook on low flame for 12-15 minutes or until the rice is completely cooked and all the flavors mingle with each other.