Wash and soak green moong dal for 3-4 hours in slightly hot water.
Meanwhile, in a pan add coriander seeds, fennel seeds, cumin seeds, and black pepper. Roast for 2 minutes and crushed into a coarse powder.
Then remove the soaked dal water and take out 3-4 tbsp dal into another bowl.
Now, add dal into a mixer jar with ginger and garlic cloves. Without adding water grind it into a coarse paste.
Take out grinded mixer into a bowl and stir continuously in one direction. After a few minutes mixer is light, fluffy, and changes its color.
Then add some soaked dal, grinded masala, salt, red chili powder, dry mango powder, hing, chopped green chilli, chopped methi leaves, coriander leaves, and gram flour. mix well.
Now add baking soda and some hot oil. Mix well into the batter.
Heat oil in a pan greases hands with water, pinch balls sized hand, and make a round shape.
Deep fry in hot oil keeping the flame on medium flame.
Stir occasionally, and fry on medium flame until the pakoda turns slightly golden brown in color.
Drain off balls from hot oil.
When it is hot, press slightly and add into hot oil to fry it again.
Fry vada on medium-hing flame till it becomes crispy and golden brown from the outside.
Serve crispy moong dal vada with tomato ketchup or chutney.