Steam the sprouts till soft. Set aside.
Heat oil in a pan and add in the cumin seeds, green chillies, curry leaves, garlic and ginger. Saute for a few seconds.
Add in the onions and saute for a couple of minutes till the onions are soft.
Add in the salt and all the spice powders. Saute for a few seconds on a low flame. Do not saute the spice powders on a high flame as they might burn.
Add in the chopped tomatoes and mix well to combine. Cover the pan with a lid and cook for five minutes till the tomatoes are mushy. Slightly mash the tomatoes so they look jammy.
Add in the sugar and half of the coriander leaves. Add in the steamed sprouts.
Add in the coconut milk and the water. Stir once.
Simmer the curry for a few minutes.
Finish with a generous sprinkle of coriander leaves.
Serve hot with rice or roti.