Heat oil in a kadai, fry the mustard seeds, urad dal, cumin seeds and dry red chillies until they turn brown, now add the finely chopped onions, curry leaves and ginger garlic paste, cook until the raw smell goes away as well as the vegetables get well cooked.
Add the snake gourd to the vegetables, saute for few minutes.
Meanwhile grind the coconut and fennel seeds in a blender as a fine paste with enough water.
Add the already cooked moong dal to the vegetables with cooked water, also add the pav bhaji masala, coriander powder and boil.
Once the curry starts boiling, add the ground spices to it and cook with lid closed until the snake gourd gets cooked well stir them occasionally.