The first time I saw purslane - when I was a child - it was growing out of a crack in a pavement in southern California. The next time I took note of it, as an adult, it was on my dinner plate. The leaves are quite easy to recognise because they're thicker than normal salad greens. The plant, which is related to cacti, thrives in dry conditions, which is one reason I saw it so often growing wild in California, where it is regarded as a weed.
The vegetable has a thick centre stem, off which leaves and smaller stems grow. The centre stem can be tough and is often discarded. When buying purslane, look for smaller leaves that are slightly glossy.
The leaves, which have a slightly lemony flavour, are often eaten raw, in salads. The sturdy texture of the leaves and tender stems can withstand hearty salad dressings. Purslane is good in a wilted salad made by frying thick lardons of pancetta until most of the fat is rendered out. Take the pancetta from the pan and into the fat whisk freshly squeezed lemon juice with a little salt and pepper. Pour the hot dressing over the purslane leaves, add the pancetta and a poached egg and serve.