We had novelty salad at the weekend with nasturtium leaves. Years ago, we planted nasturtium in the border at the back and it took over, like a Roald Dahl-esque story. For a good couple of years, we were pulling the unruly beast up. As beautiful as it is in bloom, it is as constrictive as a boa on the poor plants that get in its way. Very tasty with pea shoots, pine nuts and a creamy salad dressing.