Heat the oil in a pan.Add mustards into it. After they stop popping add turmeric(1/2 tsp), a pinch of hing, and 1 tbsp of urad dal. Once the dal turns brown add cut beans, water and cover it. Allow it to cook. It will take 15 to 20 minutes to cook. As the beans gets cooked add masala powder, salt, and 1 tbsp of lime juice. Garnish with fresh grated coconut.
Instead of masala powder you can add green chillies(ground to a paste)+1 tbsp of dhania+2 tsps of cumins