In the meantime, drain the corn from the can. Use the rest of the can for other purposes or freeze. Peel the onion and cut into fine cubes, about half the size of a corn kernel. Peel the egg while it is still warm and cut into small pieces. When I have the salad on a bread or roll, I want to be able to eat it well without having to bite through a piece of egg.
Mix all ingredients together. For me, the egg yolk always dissolves in the dressing. It has to be!
Let the salad soak through, preferably overnight in the refrigerator.
I first add herbs to garnish. I prefer flat-leaf parsley.
The quantities are so small that they fit 1 large egg and 1 serving.