Sweet Potato Salad with Creamy Yogurt Dressing

This is one of those salads that tastes better than the sum of its parts, and most of that comes from the dressing. Spring onions, cornichons and Dijon mustard do the heavy lifting. The cornichons bring a sharp, salty snap that cuts through the sweetness of the sweet potato, and the mustard gives the yogurt a little bite so it never tastes flat. If you have ever wondered why a plain mayonnaise salad can feel heavy, this is the fix: a spoonful of Greek-style yogurt keeps things light while the mayo keeps it creamy.

A small food fact that helps here: sweet potatoes hold their shape well when boiled, which is why the chunks in this recipe can stay in one piece until you are ready to dice them. Waxy vegetables like carrot and asparagus behave in a similar way, so there is no need to rush the cooking. Let the vegetables cool fully before you dress them. Warm sweet potato will soak up the dressing and turn soft and greasy, while cool pieces keep their bite.

The frozen broad beans and peas are a handy trick. Tipping them into the hot pan after you switch off the heat is enough to thaw them, and they stay bright green instead of going grey. Keep them out of the boil altogether and they will not turn to mush.

To store leftovers, keep the salad in a sealed container in the fridge and eat it within a day or so. The dressing will loosen as it sits, so give it a gentle stir before serving. It does not freeze well, because the yogurt and mayonnaise separate and the potato goes grainy, so make only what you plan to eat.

This salad sits nicely next to something warm and savoury. A piece of Cod Steaks Baked with Peas and Spring Onions makes a lovely lunch, since the peas and spring onions echo the salad. For a heartier plate, try the Smoked Paprika Sweet Potato Fish Pie alongside it, or serve a bowl of the Golden Potato and Lentil Curry on a cold evening, with the salad cooling things down on the side.