In a pot, heat the oil over medium heat. When the oil is hot, add in the black mustard seeds. When the mustard seeds begin to pop, cover the pot and turn the heat off until the popping stops.
Turn the heat to medium again, and add the turmeric and chili powder and turmeric to the pot. Add the cauliflower and peasmixture in, and stir. Turn the heat down to low and cook until the cauliflower is halfway -cooked, about 5 minutes.
In a blender, combine the tomato soup, coconut milk, tomato soup, green chilei, and 2 tablespoons of water. Blend this until smooth and add it to the cauliflower. Cover the pot and cook the cauliflower over low heat until fully cooked, about 10 minutes. Remove the pot from the heat and garnish with fresh the coriander.