1. In a wok, take 2 tbsp mustard oil. once the oil is heated, add cumin seeds and let the seeds splutter. add chopped garlic and saute it for a while on low flame.
2. Add 2 slit green chillies and cook it for a minute.
3. Add 300 gms french beans and mix everything well. cook for 3 to 4 minutes on high flame.
4. After 4 minutes lower the flame and add sliced potatoes. stir and fry everything on high flame for 2 to 3 minutes.
5. Cover with the lid and cook for 5 to 7 minutes on low flame. keep checking in between so that it does not stick to the bottom.
6. Add red chilli powder, coriander powder, turmeric powder, dried mango powder and salt to taste. mix everything well and fry for 1-2 minutes on high flame. cover with the lid and let it cook 1-2 minutes on low flame.
7. Garnish with few coriander leaves and serve hot french beans aloo with paratha or roti.