Rinse the quinoa thoroughly under cold water and drain it using a fine mesh strainer. This helps to remove any bitter residue on the quinoa.
In a kadai or a large pan, add a stick of butter and melt it over medium heat. Once the butter has melted, add the sliced onions and chopped green chilies and fry until the onions turn golden brown.
Add the ginger garlic paste and fry for another minute until the raw smell goes away.
Add all the chopped vegetables to the pan and mix well with the onion mixture. Add chili powder, haldi, and salt and stir to coat the vegetables evenly.
Add the rinsed quinoa to the pan and stir well to combine with the vegetable mixture.
Add 5 cups of water to the pan and stir gently. Bring the mixture to a boil.
Once the mixture comes to a boil, reduce the heat to low and cover the pan with a lid. Let the quinoa cook for about 15-20 minutes or until all the water is absorbed and the quinoa is fully cooked.
Once the quinoa is cooked, turn off the heat and let it sit covered for another 5-10 minutes to allow the flavors to meld together.
Garnish with freshly chopped coriander.
Serve hot. You can enjoy the mixed vegetable quinoa on its own or with a side of raita.