To improve on the traditional carp or carp and whitefish mixture, I experimented for several years with pike, trout, salmon, cod, and even halibut. I serve this gefilte fish recipe at Passover and the less ambitious gefilte fish loaf during the rest of the year.
Every Passover we recall an amusing gefilte fish incident in our house. Rachel, our third daughter was two month's old, sitting in an infant seat near the table. Deborah, our second daughter, age 5, was serving the gefilte fish course. After everyone was served (a group of 25 people), one of the guests asked why his plate was empty. Rachel was sitting non-plussed in her seat with a piece of gefilte fish on her head.
Combine all stock ingredients in the two pots, and bring to a boil. Simmer at the lowest heat, covered, while preparing fish. Grind the fish in batches, then grind onions (quite finely), challah or matzo meal, and carrots.
I use a food processor to grind the fish, but you can also chop it in a chopping bowl or have the fish monger grind it for you. Put all ingredients, as they are ground, in a very large bowl or tub. (For Passover, I use a perfectly clean dish tub. It's the only thing large enough for all the ingredients to be thoroughly mixed.)
Beat water, pepper, salt, eggs and oil in a mixer or in the food processor--this should be almost mousse consistency. Add this to the fish mixture in the large bowl or tub and mix thoroughly. (If you prefer, you can do all of this in batches in a food processor.)
With moist hands, shape 1/3 to 1/2 cup of mixture into balls, and carefully place in the simmering stock. Be cautious that you don't disturb existing pieces, but you can crowd and fill the stock with fish balls. Distribute fish in the two pots, cover, and simmer for 1.5 hours.
Let the fish cool a bit, covered.
Then carefully remove fish and vegetables
to storage containers. Strain the liquid over the fish.
Remove the carrot pieces and onions and add to the fish.
Throw away the bones,
and enjoy a "lunch" of the bits of fish in the strainer.
Store the fish for up to 7 days, well refrigerated. Serve mild or hot prepared horseradish on the side.