Wash and chop the broad beans thinly. If you are adding peanut powder, roast 1 tbsp peanuts in a microwave for 3 minutes on high power or dry roast them in a kadai. Powder them with the skin and set aside.
In a cooker base, heat oil and splutter mustard seeds, urad dal and cumin seeds. After they splutter, add curry leaves and chopped broad beans. Saute until they turn dark green. Keep the flame medium.
Add turmeric powder, sambar powder, moong dal and salt. Add 1/2 cup water and mix well. Pressure cook on high flame for 2 whistles or until the broad beans become soft.
Open the cooker after the steam is released. Mix well and check for excess water. If there is excess water, cook on high flame for 2 minutes until it drains out.
Reduce the flame to low or medium as the poriyal dries, or it may burn at the bottom. Add grated coconut or roasted peanut powder, mix well and serve with sambar rice.