Have you ever been suddenly seized with a desire for pea-soup?

Pea soup is found everywhere (and everywhen) peas are. Often it comes in the form of a humble and filling farmhouse meal, but there are luxurious versions with fresh peas, cream, wine, even champagne. And there are, of course national and regional variations. Compare matar ka shorba and snert, if you will.

Ärtsoppa, the Swedish version of pea soup, is part of the traditional Thursday night supper, either because it was a way of preparing for the Friday fast in pre-Reformation days, or because Thursday was the maids' day off and it was easy to prepare, or possibly in honour of the god Thor, who is supposed to have introduced peas to mortals.

I find the idea of the blustering god of thunder sitting down to a bowl of soup charming -- certainly a more pleasant association than the legend of the sixteenth-century monarch Erik XIV being murdered by his brother with arsenic-laced ärtsoppa.

(Erik was almost certainly poisoned, and his brother was probably complicit in the crime, but the bowl of soup as the vehicle for the arsenic may be fiction).

The possibility of murderous family members aside, I have struggled with pea soup as it's been presented to me -- with a hambone in the bottom of the pot -- and always felt bad about it. I'm supposed to like wholesome, nourishing homemade things, right? And I do like both peas and ham, so what's the problem?

I have worried about this for years. It seemed a significant personal failing, and a voice (very like my mother's) echoed in the back of my head whenever I faced a bowl of pea soup: What's the matter with you?

Well, I don't know what's the matter with me. But I think I've figured out the problem with pea soup. It's the same problem I have had with many bowls of soup made from the boiled-down remains of roast chickens: twice-cooked bones don't smell nice.

(The maternal voice in my head now says oh for heaven's sake in tones of deep exasperation, suggesting that I am the only person in the history of soup, or of leftovers, to notice this, much less to think it's a problem).

But, I protest, they don't. And furthermore stock made with overcooked bones tastes muddy and stale. I don't know why it took me so long to figure that out. Perhaps I am in fact the only person who notices, but I finally did solve it (while dutifully cooking down leftover roast chicken, as it happens). Now I know what to do about it.

The first thing to do is to stop boiling your leftover-based stock. A low simmer is fine. It's also good to learn when the bones have given up everything they can and take the stock off the heat then, not two hours later. This may take some practice.

The second thing is to take the hambone out of the soup pot. Cut the ham scraps off it and use it to make stock (at a simmer). Put the stock in your pea soup, and stir the chopped-up bits of ham into the soup when you serve it, if you like.

Or not, if you don't. This is just fine as a vegetable soup with no ham added.

I should note that Julia Child also took the hambone out of the pot when making pea soup, and used a ham stock. I did not know this until I started writing about my pea soup; I wish I'd known it years ago. There are a number of versions of her recipe around the web; the one at food.com is representative.

I use yellow split peas for aesthetic reasons -- I like the colour of the finished soup better -- but it really doesn't matter if you use green or yellow ones. The yellow does fade if you cook the peas too long (as red lentils do also) so you'll need to be careful that 'cooking until tender' does not become overcooked.

1 lb yellow split peas
2 medium-sized carrots
2 stalks celery, with leaves
1 small yellow onion
2 quarts stock (ham or vegetable -- your choice)
salt and pepper
a few sprigs flatleaf parsley, chopped (for garnish)
chopped cooked ham (optional)

Rinse the peas and place a heavy soup pot.

Wash and chop the carrots and celery in medium dice. Peel and chop the onion, also in medium dice. Add to the peas in the pot.

Add the stock to the pot and bring to a simmer over medium heat. Turn the heat down to low, cover the pot, and leave to cook, stirring occasionally, until the peas are tender, about an hour.

How long exactly the peas will take depends on their age and how tender you want them. 'About an hour' is about right for me most days but may not be right for you. Keep an eye on them.

Mash or puree the soup if you like; I like the texture of little bits of carrots and celery in the soup so I don't bother. Stir in the chopped ham, if using. Adjust the seasoning to taste. Serve garnished with the chopped parsley. A squeeze of lemon does not go amiss.

Aristophanes