Drain the liquid from the corn.
Strain the bean brine into a bowl.
Add olive oil, sugar, soy sauce and lemon juice to the filtered brine. Stir until the sugar dissolves, and change the taste if necessary.
Cut the onion into thin half rings and put it in the marinade.
Leave to marinate for 15 minutes.
Put the string beans in a salad bowl, put the corn and onion on top.
Pour the dressing in which the onion was marinated.
When serving, sprinkle the salad with sesame seeds.
