Heat a large heavy pot on medium high.
Once hot, add the brown mustard seeds and wait until they start to pop and jump around. Add olive oil to the pot and let it heat up for a minute.
Lower heat to medium and add the onions, sprinkle with salt, sauté until translucent and then add the garlic and ginger. Stir until fragrant (1 to 2 minutes).
Add tomato paste and stir to coat the onions.
Add the spices, another sprinkle of salt and stir.
Sauté the spices for about a minute and then add the sweet potato and cauliflower and stir to coat.
Once coated, add the crushed tomatoes and the coconut milk.
Bring to a boil and simmer on medium low until the veggies are tender (15 to 30 minutes depending on how large you cut the veggies).
Add the chickpeas and kale, stir to mix and simmer for another 5 minutes to warm the chickpeas and soften the kale.
Add salt and/or pepper to taste at this point.
Squeeze 1/2 a lime into the pot and stir and then serve over brown rice with a sprinkle with fresh coriander.