Cook the lentils in plenty of water on a low fire for approx. 20-30 minutes, not too soft. Pour off and quench with cold water.
For the dressing, mix all the ingredients well and season to taste. Cut the mountain cheese into small cubes. Wash the leek well and cut into thin rings and put both in a bowl, mix well with the lentils and the dressing, let it steep for a moment.
Cut the pears into thin wedges and immediately drizzle with the lemon juice so that they do not turn brown. Place the pear wedges in a circle on 2 plates. Put the salad in the middle of the pear wedges.