To a large bowl, add 1/2 cup besan (55 grams) and 1.5 cups (360 grams) yogurt. Make sure the yogurt is at room temperature. Whisk until besan and yogurt are well combined.
Add 1/2 teaspoon red chili powder, 1/2 teaspoon turmeric powder and 1 teaspoon coriander powder and whisk until you have a lump free mixture.
Add 6 cups water (around 1.4 liters of water) and mix until it's all mixed together. Set aside.
In a large and deep pan, add 2 tablespoons of mustard oil on medium-high heat. You can use any oil but mustard oil gives it a nice flavor.
Once the oil is hot (make sure oil is heated through else mustard oil gives a raw taste), add the methi seeds and cumin seeds. Let them splutter and then add hing.
Add the sliced onion along with chopped green chili and cook for 2 minutes. Then add the chopped ginger and garlic and cook for another 1 minute or so until the ginger and garlic start changing color.
Add the prepared besan-yogurt mixture into the pan. Now with heat on medium-high, stir continuously until the kadhi comes to a boil. Stir continuously until the kadhi comes to a boil, then lower the heat to low-medium and let it cook for around 30 minutes. Keep stirring it in between.
Add salt after the kadhi has been cooking for 15 minutes or so. While the kadhi is cooking, make the pakora.