Bullhead or Catfish Soup

A camp chowder reduced to its essentials: fish, water, aromatics, a little dairy and fat. The instruction "cook all together" hides the one decision that matters, which is when the milk goes in.

• Hold back the milkConsider holding back the milk -- milk held at a simmer in fish stock for a long time, or allowed to boil, can curdle. Build the soup with the water and vegetables, cook the fish, then add the cup of milk at the end and bring it back to just below a simmer.
• How long is "ready to fall to pieces"Small bullhead pieces are usually done in roughly 10 to 15 minutes of gentle simmering, thicker catfish steaks nearer 20. The recipe wants the flesh cooked until it flakes apart readily; much beyond that and it turns to cotton wool.
• Bones and skinBullheads and catfish are skinned rather than scaled, and the head and frame carry most of the flavour. Simmer the frames and heads in the two quarts of water for 20 minutes first, strain, then poach the cut flesh in that broth and pick over the fish for the few large bones before serving.
• Salt pork instead of butterIf you take the salt pork option, render the minced pork in the pot first and soften the onion and celery in the fat before adding water. That changes the soup from a plain broth to something closer to a New England chowder, and it is the better version.
• Herbs of choiceOne bay leaf, three or four thyme sprigs and a handful of parsley stems, tied together and pulled out before the milk goes in, is a sensible reading. Fish stock takes on woody herbs fast, so 20 minutes is plenty.
• SeasoningTwo quarts of unsalted water needs a real amount of salt, on the order of two teaspoons, added in stages and tasted. Salt pork will supply some of it.
• YieldTwo to three pounds of fish in two quarts of liquid makes six generous bowls as a main course. Some potato, diced and simmered in the broth before the fish, stretches it further without changing the character.