Bring a medium saucepan of water to the boil with salt. Add in the potato and cook for 7 minutes. Add the beans to the saucepan and boil for 3 minutes. Remove the pan and drain.
Meanwhile, add eggs to a small saucepan, bring to the boil and cook on a gentle simmer for 5 minute for soft-boiled eggs. Leave for another minute or two if you prefer hard-boiled eggs. Run cold water over the eggs to stop the cooking process, then peel and slice.
Assemble the potato, green beans, baby spinach, tomato, olives and eggs in a bowl. Season with salt and pepper.
Whisk together the dijon and olive oil.
Pour the dressing over the salad and gently toss to combine. Serve.