Foraging for Japanese knotweed (polygonum cuspidatum) is not only worthwhile in terms of finding a delicious and nutritious food source. You will also be doing the environment a big favour, as it is arguably the most invasive of all invasives. Initially we tackled a large grove of it growing in our front garden with the lawnmower. We almost succeeded when it occurred to me this might be an interesting wild food, at which point I salvaged a few sprouts, transplanted them to an appropriate area and have just begun to harvest them. If you are not familiar with this plant, here are a few characteristics which should help you identify it. Where to find it: Along roadsides, riverbanks, fields where the earth has been disturbed. Originally from South East Asia it now grows in North America, Europe, Australia and Tasmania. How to identify it: It is usually grown in clumps and resembles bamboo with its hollow stems. The stems are green, spotted with red and divided by joints, or knots. The young shoots are deep red. The leaves are smooth-edged, hairless and broad oval in shape with a pointed tip and hanging from a long stem. Edible parts: The young leaves and stems before they attain a height of about a foot are commonly used. The rhizomes are usually reserved for medicinal purposes. As I contemplated my modest haul, I was wondering how best to prepare them. I must have had a flash from the past, because suddenly the word ‘strata’ popped into my head, a word I have not heard in decades, but am familiar with the dish. That seemed a good place to start, as it involves few ingredients and no strong flavour which might overpower it. Strata is often made to use up old bread, typically with vegetables and sausage (or ham/bacon) and cheese and cooked in a custard. I used a crusty sourdough bread, but any crusty good quality bread will do. I only used cream cheese because a stronger cheese would just be too much flavour, but a hard cheese could be grated on the top if you like. I omitted meat, and pumped up the vegetable content with lots of caramelized onion. Having tasted some raw bits, I thought it tasted like a gentle rhubarb, so used sumac and mustard to pair with the fruity flavour.
This dish lends itself well to all sorts of variations, but I was very pleased with it just as it was. Perhaps if we all made use of this remarkable vegetable, it would not be such a pest.
Ingredients 2 cups Spanish onions, sliced thin oil for frying 2 cups chopped knowtweed stems 2 cups leaves, tightly packed 4 cups bread cubes 1 cup cream cheese 4 eggs 3/4 cup cream (18%) 1/2 cup milk 1 tsp salt 1/2 tsp ground pepper 1 Tbsp sumac powder 1 tsp mustard powder Method Fry the onions in oil gently until they begin to caramelize, about 20 minutes. Add the knotweed stems and continue to fry about five minutes longer, until the stems are cooked. Add the leaves, cover the pot and cook gently until the leaves are wilted. Set aside to cool. Meanwhile, place the bread cubes in a casserole in a 325 degree oven until they are slightly toasted. Mix together the cheese, eggs, cream, milk, seasoning and spices until they are well blended. To assemble, grease a casserole dish lightly and place the bread and vegetable mixture in it, stirring gently to combine. Pour the cheese mixture evenly on top, making sure that all the bread is soaked. Place in a 350 degree oven for about 40 minutes until it is brown and crisp on top and cooked through.