Add the quinoa, vegetables, turmeric, and 6 cups of the water to a large pot. Bring to a boil, then lower the heat, cover with a lid, and simmer for 30 minutes.
While the vegetables are cooking, add the remaining ⅓ cup of water, chilis, cumin seeds, asafoetida, if using, and fenugreek seeds to a large pan. Sauté for a few minutes, then add the tomatoes, coriander, cayenne, and garam masala. Simmer for about 5 minutes.
Stir the tomato mixture into the pot with the quinoa and vegetables. Cook for about 5 minutes.
Add the soymilk and stir together until well-combined. Cover the pot and cook for 5 to 10 minutes.
Remove from the heat and serve garnished with chopped cilantro or parsley.