Purslane, also known as duckweed, is an edible weed that is purported to have significant health properties, namely disease fighting phytonutrients. But it's more than just a nutritional powerhouse; it's also a great source of distinctive and wonderful herbal flavor. Here, purslane is added at the last minute to a mixed vegetable soup that includes zucchini, carrots, butter beans, and pumpkin. Be sure to cut the vegetables into uniform pieces so they cook at the same rate and end up being tender but still with a bit of bite.