Cook the pasta until it is still a little al dente (2 mins less than the pack instructions) and drain well. Cook the green beans in simmering water for 2 mins, then rinse in cold water and drain well. Mix the tuna with the mayonnaise and yogurt. Add the chives, if using.

Tip the pasta into a large glass bowl or four small ones, or four wide-necked jars (useful for taking on picnics). Spoon the tuna dressing over the top of the pasta. Add a layer of green beans, followed by a layer of cherry tomatoes, then the pepper and sweetcorn. Cover and chill until you’re ready to eat.