There are a couple of elements here, which in my view, turn this from a standard (if lovely) beetroot and goat's cheese salad into something more interesting and vibrant. The first is the pickled turnip, which is the easiest thing in the world to make, and adds a rasping sharpness to the dish. The other is the watercress purée, which alongside the sweet beetroot and tangy goat's curd, provides a useful, vegetable-y bass note.
Nasturtium leaves are good if you can get them. They’re deliciously peppery and look pretty to boot, and can be found, among other places, in certain summer garden salad bags. Any other leaves will work fine though – pea shoots, rocket, watercress, whatever you have handy.
Ultimately there’s little cooking or skill needed here for what is a cracking summer starter dish. By now you’ll probably know that I’m a big goat's curd fan. You can cheat, if you lack the time or inclination, by mixing soft goat's cheese with a little natural yogurt.