I was on the phone to Mum while having lunch. “This is seriously good soup,” I told her. “Yes…” Mum tried to get the conversation back on track. “I mean, really good,” I insisted, making lots of appreciative noises, which really is a bit boastful considering I invented the soup. “Aha,” she sighed. “Okay, if it’s that good, why don’t you write it down so I can cook it?”
It’s actually a simple sweet potato and watercress soup. I tried watercress soup with regular potato, but wasn’t that impressed, so one day hit upon using sweet potato. Okay, others have already been there before me, but I wasn’t aware of it at the time! Because of the watercress, I’ve called it Susanna’s Soup. Susanna, daughter of Shakespeare, married a local physician, John Hall, who used watercress in his medicines to treat scurvy. I became interested in her after seeing The Herbal Bed (I saw the 1996 production with Joe Fiennes and David Tennant!) and visiting their house in Stratford-Upon-Avon, which still has a gorgeous herbal bed.
Anyway, to the soup! As always, I never measure accurately, so… sorry. Every time I try to do the whole measuring thing, it goes horribly wrong. I’ve tried to give good estimates, though, and with soup, these things are pretty forgiving. This makes two generous servings – three normal servings.
First, you put a little olive oil in the bottom of the saucepan and fry up a generous handful of diced speck. Once it’s nice and brown, toss in a diced stalk of celery, one diced carrot, and about 5 garlic shoots chopped into 1/2 inch pieces (if you can’t get garlic shoots, you can use one or two cloves of garlic and a handful of chopped spring onion). While that’s all frying nicely, chop up one large-ish orange sweet potato and add to the pot. Let that cook for a few minutes.
Then add a few pinches of coarsely ground black pepper (I tend to do quite a few pinches – I like my soup peppery), roughly 500ml of good chicken stock, a good slosh of white wine, the juice of half a blood red orange and if you need a little more liquid, just a bit of water.
Let that simmer away until the sweet potato is all soft and squishy. Add a bunch of watercress, all chopped up.
Once the watercress has had a few minutes to soften up and cook, whiz it up. I like to leave it a little chunky.
You can then serve it with a blob of sour cream, or, in my case since I have to go light on the dairy, Tofutti cream cheese.
I tried to take a really artistic photo, but this will do! Just forgive that bit of watercress stalk that missed the whizzing stage.
It really is fantastic soup and full of great sources of vitamin C as a bonus!