Bengalis share their love of whole black mustard seeds with South Indians, but unique to Bengal is the extensive use of freshly ground mustard paste. A pungent mustard sauce called Kasundi is an dipping sauce popular in Bengal.
Ingredients
50g fresh ginger, peeled
50g garlic cloves, peeled
2 green chillies, split and de-seeded
1 large onion, peeled and roughly chopped
½ cup vegetable oil
1 tbs black mustard seeds
2 sprigs curry leaves
1 tbs turmeric
2 tbs ground cumin
1 tbs paprika or 1 teaspoon chilli powder (or a combination)
1 tbs dry mustard
½ cup brown malt vinegar
1½ kg roma tomatoes washed and roughly chopped
1 cup sugar
1½ tbs salt
Method
Blend the ginger, garlic, chillies and onion to a paste in a blender.
Heat a large pot, add half of the oil and all the mustard seeds and fry until they 'pop'. Add curry leaves and stir as you add them as they will splutter. Add the remaining spices and garlic/chilli paste, cook another minute until fragrant.
Add the remaining ingredients and bring to a boil. Reduce heat and simmer, stirring occasionally, for about 1 hour or until thick and 'jammy'.
Spoon 'kasundi' into sterilized jars, top with some of the remaining oil. Cap and store in refrigerator — improves with age.