Cook the eggs. Place the eggs in a saucepan and cover with cold water. Bring to a boil and cook for 6 minutes. Turn off the heat and allow the eggs to cool in the water until the yolks are fully set.
Cool and peel. Run the eggs under cold water until cool enough to handle. Gently peel and transfer to a mixing bowl.
Mash the eggs. Using a fork, mash the eggs to your preferred consistency. I like to leave a few larger pieces for texture.
Mix the egg salad. Add the mayonnaise, Dijon mustard, whole-grain mustard, olive oil and finely chopped celery. Gently mix until everything is combined.
Season to taste. Add sea salt and freshly ground black pepper. Taste and adjust the seasoning as needed.
Serve. Enjoy on toasted sourdough, on your favourite sandwich bread or simply spooned over fresh greens.