Heat the oil in a large pan over medium heat.
Add the chopped onion and sauté until golden brown.
Stir in the minced garlic and grated ginger, cooking for 1 minute.
Add the chopped tomatoes and cook until soft.
Mix in the curry powder, turmeric, and cumin, stirring well.
Add the chicken pieces and cook until browned on all sides.
Pour in the coconut milk and bring to a simmer.
Reduce heat, cover, and let it cook for 20 minutes.
Season with salt to taste and stir well.
Garnish with fresh cilantro before serving.