Method:

1. Dry roast the bean for few mins(optional , I didnt do it this time) and soak it in water overnight or for atleast for 8 hrs.Soak the tamarind in warm water and extract thick pulp. Few readers asked me to show the quantity if tamarind so here it is for you :)
2. Pressure cook beans for 5-6 whistles or until soft.Set aside. In a kadai heat oil - saute the ingredients listed under 'to saute and grind'  and grind it along with coconut and fennel seeds.
3. Grind it to a fine paste,Set aside. In a kadai heat oil - add the ingredients listed under 'to temper' allow it to splutter then add onion, tomato and garlic saute till raw smell of tomatoes leave.
4. Then add the cooked beans along with the water, then add tamarind pulp. Allow it to boil for 3mins or until raw smell of tamarind leaves.Add required salt.
5. Then add the coconut paste along with red chilli,coriander powders and required salt. Add 1/2 cup water if the mixture is too thick.Allow it to boil for 5-10mins until oil separates.Boiling for little more makes the curry thick and tasty too.Switch off once you get the desired consistency.

My Notes

• You can add in other veggies along with mochai like brinjal,drumstick etc etc.You can even use fresh beans for this recipe
• Boiling for more time gives the gravy a nice flavour.
• Allow atleast 30mins sitting time for the mochai to absorb the curry well. Also this kuzhambu thickens with time so adjust and switch off accordingly.
• While tempering, you can even add cinnamon, cloves instead of mustard and urad dal.