Heat the vegetable oil in a large pan over medium heat.
Add the cumin seeds and sauté for about 30 seconds until fragrant.
Add the chopped onions and sauté until golden brown, about 7-8 minutes.
Stir in the ginger-garlic paste and cook for 1-2 minutes.
Add the chopped tomatoes and cook until they break down and the oil separates, about 5-7 minutes.
Stir in the coriander powder, turmeric powder, and garam masala; cook for 1-2 minutes.
Add the sliced mushrooms and mix well; cook for about 5-6 minutes until they soften.
Pour in the coconut milk and mix until combined; simmer for 5 minutes.
Taste and adjust seasoning with salt as needed; garnish with fresh cilantro before serving.