Put prunes into the bowl with COLD water for the night (at least 10 hours) to soak good.
Boil beet roots in the pressure cooker 1-1.5 hour (depending of size), when ready cool them down and peel. Shred beet roots using a coarse shredder, add a pinch of salt and 50g of mayonnaise, mix well and put into the salad bowl.
Take prunes out of the water and dry a little with kitchen towel. Gently remove the stone and fill them with piece of walnuts. Replace stuffed prunes up on the beet salad.
Prepare dressing: 50g mayonnaise, 1clove garlic minced, 1 teaspoon while sugar mix good and put on the prunes, garnish with 2 tablespoons dill.