Take a pressure cooker and add in drumstick, sliced tomato, onion, chilies, curry leaves, chili powder, turmeric powder, salt, and water. Pressure cook for 2 whistles on medium flame.
Open the pressure cooker once the pressure releases and add coconut milk and boil.
Heat another pan and splutter mustard seeds. Add in curry leaves and red chilies. Saute and add this to the curry and serve with rice.
Recipe by Kerala Cooking Recipes at https://www.keralacookingrecipes.com/drumstick-tomato-currymuringakka-thakkali-ozhichu-curry/