From the 1881 Household Cyclopedia

Leave 1 pint of peas in the pot with the water they were boiled in; make a thickening of flour, milk and butter, seasoned with salt, pepper, parsley and thyme; toast 2 or 3 slices of bread, cut it up in the tureen; and when the soup has boiled about 10 minutes, pour it over.

Children are mostly fond of pea soup, and it seldom disagrees with them. A few slices of fat ham will supply the place of butter.

see Wikipedia Cookbook

Modernized:

  1. Open a package of dried green or yellow peas and discard any small rocks you may find.
  2. Place the peas in a cast-iron or thick aluminum pot or a crock pot. Add water to cover. Boil over low heat for the time recommended on the package.
  3. (Optional) - Add a handful or less of chopped carrots.
  4. (Optional) - Add butter and/or cooked ham hocks and/or chunks of cooked ham.
  5. (Optional) - Season with salt, pepper, parsley, and/or thyme to taste.
  6. If you prefer a thicker soup or a milk-based soup, stir milk into flour and then add the mixture to the soup when it is nearly finished cooking.
  7. If you prefer a smoother soup, pass it through a food mill or lightly process with a food processor.
  8. Serve in individual soup bowls.
  9. (Optionally) - Garnish with a floating dollop of sour cream, croutons, and/or a sprig of fresh mint.
  10. (Alternatively) - Slice off the top fifth from a Cob loaf. Hollow out the loaf then generously butter the inside of hollowed loaf (the loaf should resemble a bowl). Use the removed bread for croutons, and fill the hollowed loaf as a serving bowl. Use one Cob loaf per person.

For people who haven't got that much time:

  1. Open a can of pea soup.
  2. Pour the contents into a microwavable casserole or individual soup bowls.
  3. (Optional) - Add parsley, sage, oregano, and/or thyme.
  4. Cover with the lid or with vented cling wrap.
  5. Nuke for 2-3 minutes.
  6. (Optional) - Garnish with a floating dollop of sour cream, croutons, and/or a sprig of fresh mint.

Extra serving suggestion:

In the south of the Netherlands rye bread (roggebrood) is also served. The meat is put on the rye bread and eaten with mustard. Absolutely delicious.