Wash and chop 500 grams of ripe tomatoes into small pieces.
Heat 2 tablespoons of oil in a pan over medium heat. Add 1 teaspoon of mustard seeds and let them splutter.
Add 1 finely chopped onion and 2-3 finely chopped green chilies. Sauté until the onions turn golden brown.
Add 1 teaspoon of ginger-garlic paste and sauté for another minute.
Add the chopped tomatoes, 1/2 teaspoon of turmeric powder, 1 teaspoon of red chili powder, 1 teaspoon of coriander powder, and salt to taste. Cook for 10-12 minutes, stirring occasionally, until the tomatoes are soft and mushy.
Add 1 cup of coconut milk and 1/2 cup of water to the pan. Mix well and bring the curry to a boil.
Lower the heat and let the curry simmer for 5-7 minutes, allowing the flavors to blend.
Garnish with chopped coriander leaves and serve hot with steamed rice or roti.