This section is from the book "The Memorandum Cookery Book", by Countess Morphy. Also available from Amazon: The Memorandum Cookery Book.
Here is another very uncommon hors d'œuvres, made of the much despised dry salt cod, so seldom seen on the table in England.
1 lb. of dry salt cod, 4 or 5 small potatoes, boiled in salted water, 2 herring roes, 2 hard-boiled eggs, 1/2 an onion finely chopped, 2 dessertspoons of capers, 1 dessertspoon of tarragon, fennel, and chervil, also chopped, 3 tablespoons of salad oil, 1 1/2 of wine vinegar, 1/2 a teaspoon of made mustard.
Soak and cook the cod as described in recipe for Dry Salt Cod Saute on page 54 and remove the bones, etc., and place the flaked fish in a salad bowl. Mix well with the potatoes, which must be thinly sliced. Garnish all round the dish with thin slices of hard-boiled egg, put the capers in the centre and around these the onion and chopped herbs. Serve the following sauce separately in a sauceboat: Soak the roes in a little milk, put in a small saucepan of cold water, bring to the boil and poach for a few minutes till tender. Drain and rub through a sieve into a basin. Season highly with salt and pepper, and add the mustard. Now work in the oil gradually as in making mayonnaise and lastly add the vinegar.