Open the tin of tuna fish and drain water and put into a mixing bowl
Add the mayonnaise and mustard and mix into the tuna without breaking the tuna down too much
Chop the cornichons into litte bite-sized pieces and add into the tuna mix with the capers. This adds bite and a sharpness to contrast with the soft taste of the tuna.
Place the final salad into a container ready for lunch.
You can serve with rice cakes, red pepper sticks as "dippers" and a folding fork to add a little bit more interactivity and sense of a picnic.