Smoked mackerel is a delicious oily fish and an ideal substitute for tuna in this salad, packed with protein. Although you can use the traditional Niçoise ingredients, it's really adaptable depending on what you like, what you've got in the fridge and how many you are serving! Potatoes are optional for the carb dodgers! This is a lovely summery supper, lunch or to use as a filling for wraps.
If I'm thinking ahead, I'll boil some extra green beans and potatoes with dinner the night before so I only have to think about boiling the egg for lunch.