"She used a ham hock," he replied, "...onions, leeks, and potatoes - obviously." He remembered she added some milk, too, and served it up as a rustic broth, swimming with chunks of potato.
I set out to make my own version. Unfortunately, the local butcher had sold out of ham hocks. Instead, he provided me with some bacon trimmings. I cut these into medium dice and fried them gently in in beef dripping until they started to render their fat. To this I added an onion, a leek, and 2 sticks of celery, all finely chopped, and let them sweat, with a lid on, for 10 minutes or so. Next went in a good 500g peeled and diced potatoes, a bay leaf, 200ml milk, and enough water to cover (ham stock would be better). I brought this to a boil then let it simmer until the potatoes were tender and falling apart - about 30 minutes. Seasoned well with salt and pepper and served piping hot - not fit for a king, perhaps, but good enough to invite a neighbour to join us for supper.
I decided to give this another go when I got back to Cambridge and could get my hands on a ham hock - this is where last week's ham stock went to. I also wanted to intensify the earthy potato flavour, so cut down on the other vegetables and, following the lead of Heston Blumenthal, who cooks his potatoes in a stock made from their skins, included the potato skins in my soup. Here's the recipe I came up with.
Ray's potato soup
- 25 g butter
- 1 onion, finely chopped
- 1 bay leaf
- 1 kg floury potatoes, peeled and diced, skins reserved
- 1 lt ham stock
- 300 ml whole milk
- salt and pepper
As you see, this is a soup of few ingredients. It's important to use a floury potato variety (I used King Edward), otherwise the finished soup will have an unpleasant gloopy texture.
Melt the butter and sweat the onion, without colouring, for 2-3 minutes. Add the potatoes and cook gently, with a lid on the pan, for at least 10 minutes. You will have to stir them from time to time to prevent the potatoes from sticking. Now add a bay leaf, 1tsp salt, and the stock and milk. Tie the potato skins up in muslin and add this to the pot. Bring to a boil, then reduce the heat and simmer gently until the potatoes are cooked through. Remove and discard the package of skins.
To finish, blend in a liquidizer until smooth. (In retrospect, I think simply pushing the soup through a fine sieve would result in a better texture, as it would work the starch less.) If you have ham left over from your stock-making, add this to the soup when you reheat it. Season to taste with salt and pepper.
For a real treat, omit the ham and serve each bowl of soup with a generous drizzle of truffle-infused olive oil.
Jane Grigson, in her Vegetable Book, gives a recipe for potato soup flavoured with lard and garlic, "...which both blend wonderfully with potato." She suggests serving this with croutons, also fried in lard and garlic. This is definitely something I'll try soon.
In Fergus Henderson's Beyond Nose to Tail, he gives a recipe for Potato and back fat soup. This recipe also plays on the pork fat and garlic theme: the soup is made with 10 cloves of garlic and topped with chunks of salted back fat rendered in a frying pan. Henderson writes: "But our possibilities do not end there. You could instead sear off a generous slice of fresh foie gras per bowl of soup, pop on top of the hot soup and give it a few minutes to do a little melting, then eat."
Who said that potato soup had to be boring?