Ingredients:
                                              1 cup field beans/vaal  dal
1 tablespoon oil
1 tablespoon mustard seeds/rai
1 spring curry leaves/patta
1 onion, chopped
1 teaspoon ginger-garlic paste
1 teaspoon garam masala
2 big sweet potatoes, peeled & cut in large pieces
1 lemon, juiced
2 tbsp coriander  leaves, chopped 
                                                
                                                Preparation: 
                                            Boil vaal dal with  water till mushy. Mash smooth and keep aside.
Heat oil and fry  mustard seeds, curry leaves and onion followed by garam masala and  ginger-garlic paste.
Add sweet potatoes. Cook till they soften.
Add boiled vaal dal, salt with some water. Cover and simmer.
Add lemon juice just  before serving and garnish with coriander leaves.
                                            
Serve with rice or 
rotis.