Wash the potatoes, cover with skin and cook in boiling water for about 15 minutes. Drain the potatoes, rinse with cold water and peel off the skin. Let them cool down.
Wash and clean the beans and cut them diagonally into bite-sized pieces. Wash the savory and shake dry. Cover the beans and savory and cook in a little boiling salted water for 8-10 minutes. Drain, drain and remove the savory.
For the Dijon cream, peel and dice the shallots. Wash the chives, shake dry, cut into fine rolls. Mix vinegar, mustard, cream, salt, pepper and approx. 1 teaspoon sugar, fold in oil.
Stir in chives and shallots. Mix potatoes, beans and Dijon cream. Leave to stand for about 1 hour.
Boil eggs for about 10 minutes, quench cold and let them cool down. Drain the tuna and fold into the salad. Peel and halve the eggs. Season salad again with salt and pepper. Serve with the egg halves.