Heat oil in a large pan over medium heat. Add cumin seeds and asafoetida; sauté until aromatic.
Add chopped onion and sauté until golden brown.
Stir in grated ginger, minced garlic, and slit green chillies; cook for 2 minutes.
Add cubed potatoes and sauté for 5 minutes until slightly browned.
Add green peas, coriander powder, cumin powder, turmeric powder, red chilli powder, dried mango powder, and salt. Mix well.
Cover and cook on low heat for 10–12 minutes, stirring occasionally, until potatoes are tender.
Sprinkle garam masala over the dish, mix gently, and cook for an additional 2 minutes.
Garnish with fresh coriander before serving.
