Drain the apricots well in a sieve, collecting the juice. Measure out 100 ml of juice. Wash the meat, dab dry and cut into 4 pieces. Heat oil in a pan and fry meat for 3-4 minutes on each side.
Season with salt and pepper. Remove from the pan and drain on kitchen paper. Remove the paper from the puff pastry slices and let the puff pastry thaw on the work surface for about 10 minutes at room temperature side by side.
Whisk the egg yolk and 2 tablespoons of water. Cut cheese into 8 pieces. Then roll out each slice of puff pastry to a square (approx. 15 x 15 cm) on a floured work surface. Sprinkle 1 teaspoon of breadcrumbs in the middle of each, place one piece of meat in the middle of each, spread the cheese on top and place 2 apricot halves on each.
Wrap the sides of the puff pastry and close it to form a package. Brush with whisked egg yolk. Place on a baking tray lined with baking paper, leave some space between the packages and bake in a preheated oven (electric range: 200 °C/ convection oven: 175 °C/ gas: level 3) for 20-25 minutes.
Meanwhile, for the sauce, put the remaining apricots, honey, mustard and 100 ml apricot juice into a tall mixing bowl and puree. Coarsely chop the walnuts. Clean and wash the salad and drain well in a sieve.
For the vinaigrette, mix vinegar, salt, pepper and sugar well. Fold in olive oil. Mix salad, vinaigrette and walnuts. Remove the puff pastry packs from the oven and arrange on plates with some sauce and salad.
Add remaining salad, packet and sauce extra.