Place eggs in boiling water and cook for 8 minutes until firm.
Drain sardines and gently break them into bite‑sized pieces.
Rinse beans thoroughly and drain to remove excess salt and brine.
Cut cucumber into thin half‑moons for a refreshing crunch.
Peel the cooled eggs and chop them into even pieces.
Combine yoghurt, mustard, salt and black pepper in a small bowl.
Place beans, sardines, cucumber and eggs into a large bowl.
Pour the dressing over the salad and toss lightly to coat.
Chill the salad for 10 minutes to enhance flavour and texture.
Serve immediately or store in the fridge until ready to enjoy.