Step 1

Clean and boil the green beans for 10 minutes in boiling water. Drain them and let them rest until cold in the refrigerator.
During that time, open the tuna and use a fork to separate it into small chunks. Cut the green onions into small pieces.

Step 2

When cold put the beans in a bowl, the tuna and the green onions altogether.
Add the equivalent of 4 teaspoons of lemon juice and 1 teaspoon of mustard. Mix them together.

Step 3

Add salt and pepper to your taste. Mix once again and serve in small bowls as a starter.