It's possible that you've never heard of this vegetable........ it's certainly not in the supermarkets, and yet its been around for thousands of years.
Jerusalem artichoke (Helianthus tuberosus), also known as 'Sunchoke' is a very hardy, easy to grow, perennial vegetable which means you only ever have to buy it once!
In the kitchen, the bulbous root has a sweet, nutty, creamy, potato-like flavor with a texture similar to chestnuts, and may be eaten raw, roasted, fried, or puréed into soup. You pretty much treat them like a potato however they don't need peeling - just scrub them well. They may be added to regular mashed potato for a different nutrient profile or roasted (unpeeled) at 
200'C with oil and thyme for a crisp texture. They may also be dried and ground into flour.
All sounds great doesn't it, but.............BEWARE!!!!! Jerusalem artichokes cause significant gas because they are high in inulin, a fermentable prebiotic fiber that bacteria in the colon break down. This may lead to flatulence, bloating, and cramping. To reduce this effect, cook them slowly with acidic ingredients like lemon juice or vinegar.
GROWING
Select firm tubers with few knobby bits, ensuring that each piece has at least one "eye" or bud. Plant with the eye pointing up, around 10-15cm deep. Plants should be spaced around 40cm apart keeping in mind that they will grow quite tall - up to 3m.
CARE AND MAINTENANCE
Keep the soil moist, but not waterlogged. Mulch well. Cut stems down to about 4 feet to encourage larger tuber growth.
HARVEST
Tubers are ready for harvest in late autumn, after the first frost, or as the stalks die back. Dig up as needed. They may also be left in the ground and harvested throughout the winter.
Remember to keep a few bulbs for replanting next season.