Ingredients:

  Amount  Measure       Ingredient -- Preparation Method
--------  ------------  --------------------------------
   8                    bhetki/beckti fillets (fish)
                        oil for shallow frying
                        ***FOR THE MARINADE***
   3      tablespoons   lemon juice
     1/2  teaspoon      turmeric powder
                        salt to taste
                        ***FOR THE FISH STOCK***
   1      liter         fish stock
     1/2  teaspoon      cumin seeds
     1/2  teaspoon      fennel seeds
     1/4  teaspoon      fenugreek seeds
     1/4  teaspoon      yellow mustard seeds
     1/4  teaspoon      kalonji seeds
                        ***FOR THE GRAVY***
   6      tablespoons   mustard oil
     1/4  teaspoon      kalonji seeds
   4      whole         red chiles
   2                    bay leaves
   4      tablespoons   mustard seed paste
   3                    onions -- grated
   4      teaspoons     ginger paste
   1      tablespoon    coriander powder
   1      teaspoon      cumin powder
   1      teaspoon      Kashmiri deghi mirch
   1      teaspoon      turmeric powder
   4                    green chiles -- halves and deseeded
                        salt to taste

Preparation:

To prepare the fish stock: Put all the ingredients in a large pot and bring to a boil. Lower the heat and simmer until reduced to half its quantity. Remove from heat. Pass through a fine mesh soup strainer and keep aside. Mix all the ingredients for the marinade in a bowl and evenly rub the fish fillets with this marinade and reserve for at least 20 minutes. Heat oil in a frying pan and shallow fry the marinated fillets over medium heat until golden. Remove to an absorbent paper to drain the excess oil. Heat mustard oil to a smoking point in a flat pan (or kadai or wok). Remove from heat and cool. Reheat the oil and add kalonji seeds, whole red chiles and bay leaves. Stir until the chiles become bright red (not brown or black), add the mustard paste and stir-fry until the oil floats on top. Add the onions and sauté until translucent and glossy. Add ginger paste and stir-fry until the onions are golden (not golden brown). Dissolve coriander powder, cumin powder, deghi mirch powder and turmeric powder in 1/4 cup water and add to the pan. Stir-fry until almost dry. Arrange the fish in a single layer, place the green chiles on top, pour the hot fish stock over. Bring to a boil. Lower the heat and simmer, gradually pouring the stock over the fillets, until cooked for about six minutes. Remove and carefully adjust the seasoning.