Jerusalem artichokes - What are they?
Jerusalem artichokes (Helianthus tuberosus) are one of those vegetables those only vegetable fans know about. They're not easy to find in shops - I first encountered the knobbly tubers in an organic vegetable box last year.
But they're probably about to get very trendy. Not only are they a common crop on allotments (community gardens), but they contain inulin - An indigestible starch which a) makes you fart, b) makes them very low calorie and c) is considered to be a "pre-biotic", helping to feed colonies of good bacteria in the gut.
Growing Your Own
Jerusalem artichokes are fabulously easy to grow - they are rampant beasts that thrive in tough conditions. In fact, if you let them loose in your garden you may never be rid of them again.
If you don't have a vegetable plot, or don't want them to run riot, then plant them in a tub on the patio for a very low-maintenance crop. I planted four tubers from my vegetable box (you can plant tubers intended for eating with no problems) in January 2006 into 12" tubs of compost and they sat on my patio throughout a long, hot summer. I watered them sometimes, when they were wilting. I also staked them when they got tall as in pots they never grow thick enough to become the windbreak they're famed for being. But mostly I just left them there - they're that easy to grow.
In January 2007 I tipped out one of the pots and each little tuber had turned into half a dozen large tubers, enough to make Jerusalem artichoke and sweet potato soup. They weren't even that knobbly, and eaten fresh there was very little waste. It might not have been the largest yield ever, but considering the lack of care and attention they got, it was very energy efficient!
I chose the smallest of the tubers and replanted it in the same pot, with fresh compost. I watered it in and gave it a mulch of bark chips and put it back on the patio for next year.
If you order Jerusalem artichokes from a seed catalogue they may well be the variety Fuseau, which is generally thought to be the least knobbly. They will arrive for planting in February/ March, but if you have some earlier than that you can still plant them out - they're very hardy and as long as they don't get waterlogged they should be fine.
Eating Them
Jerusalem artichokes can be eaten raw in salads, but are generally used in much the same way as potatoes. They can be mashed or made into chips. They're excellent in soup, giving a creamy texture and a slightly smoky taste.
Vegetable soup in our house is a bit haphazard, made of whichever vegetables are handy. Artichokes go very well with carrots and, we discovered after another vegetable box delivery, sweet potatoes.
In either case, sweat an onion in some oil (with garlic if you like it), throw in some dried herbs (optional) and then peel and dice your vegetables (for 2 people I used my artichoke harvest plus 2 sweet potatoes). Recipes I have seen say you should put peeled artichokes under water as they rapidly discolor, but I just throw them into the pan as I finish chopping them up and have never had a problem.
After frying them for a couple of minutes, cover the vegetables with stock (broth). I use vegetable stock but you could use chicken (or homemade stock if you're lucky enough to have it). The stock to vegetable ratio governs how thick the soup will be later. Put a lid on the pan and leave the vegetables to simmer until they're tender. This part can be done in a slow cooker if you're going out for the day.
Once the vegetables are cooked, put the soup in the blender and blend until you have a consistency you're happy with. You can adjust the liquid at this point, adding more stock or some milk if the soup is too thick.
The soup reheats well, but doesn't keep for too long - if you want to keep it for more than a couple of days then freeze portions rather than leaving them in the fridge.
