In a wok or a pot, add oil.
Once hot , add in the mustard seeds.
Once mustard seeds crackle, add the curry leaves and Asafoetida.
Now add in the finely chopped onion, garlic, ginger and green chillies.
Saute until onion is translucent.
Add the chopped tomato, turmeric powder, red chilly powder and salt.
Give everything a mix and let it cook until the tomatoes are cooked and masala looks like mixed properly.
Now add the washed and diced vegetables. I.e. Cauliflower, potato and green peas.
Mix in everything. Cover and cook on slow to medium stirring in between.
Read above on how to cook in less oil and without water.
Check if the potato is done after 8-10 minutes. The Sabzi is done when you prick or cut the potato with a spoon and it cuts easily or When you mash a green peas, and it gets mashed easily.
Garnish with Chopped Coriander and serve it with roti or rice.