Slice the tops of tomatoes. With a small spoon, scoop out all seeds and remove some of the dividing walls, leaving three or four large sections. Don’t squeeze the tomatoes. Sprinkle with salt and turn the tomatoes upside down to let excess liquid drain out.

Rinse the shrimp in cold water. Full a pot with 2 quarts water. Add vinegar and salt and boil. Drop in the shrimp and cook. Drain, shell and devein the shrimp. Set aside to cool.

Set aside 6 shrimps. Chop the rest not too fine, put them in a bowl, and mix them with mayonnaise, capers and mustard

Shake off the excess liquid from tomatoes without squeezing them. Stuff to the top with the shrimp mixture. Garnish each tomato with shrimp and parsley

Serve at room temperature or even just slightly chilled