Wash and cut 2 drumsticks into 2-inch long pieces.
Grind 1 cup of grated coconut, 1 teaspoon of cumin seeds, and 2 green chillies into a smooth paste with a little water.
Heat 2 tablespoons of coconut oil in a pan. Add 1 teaspoon of mustard seeds and let them splutter.
Add 1 finely chopped onion and sauté until it turns translucent.
Add the drumstick pieces to the pan and sauté for 2 minutes.
Pour 2 cups of water into the pan, cover, and cook until the drumsticks are tender.
Add the ground coconut paste, 1/2 teaspoon of turmeric powder, and salt to taste. Mix well.
Allow the curry to come to a boil, then simmer for 5 minutes.
For tempering, heat 1 tablespoon of coconut oil in a small pan, add 1/2 teaspoon of mustard seeds, a few curry leaves, and 2 dry red chillies. Once the mustard seeds splutter, pour this over the curry.
Serve hot with steamed rice or roti.