4 cups peeled and cubed potatoes
1 1/2 teaspoons salt, divided
1 11-ounce pouch (or canned) chunk tuna in oil, undrained
1/4 cup pitted and chopped Greek olives
1/4 cup minced red onion
1/4 cup minced parsley
1/2 teaspoon freshly ground black pepper
2 tablespoons Dijon mustard
1/4 cup red wine vinegar
2 tablespoons olive oil
Parsley sprigs


Boil water in a pot. Add potatoes and add a teaspoon of salt. Let it simmer for 18 minutes. Take the pot off the stove top and drain. Separate tuna from its oil, reserving the latter. Chop the tuna into small portions and transfer it in a moderate-sized bowl.
Put the potatoes, olives, onion and parsley into the bowl of tuna. Combine the reserved oil along with 1/2 teaspoon salt, pepper, Dijon, red wine vinegar and olive oil. Once smooth, add it into the bowl of tuna and potato, tossing lightly until coated. Serve with parsley sprigs as garnish.