Rinse lentils in cold water. Cook with a little vinegar in plenty of water for 25-30 minutes until soft. Drain, rinse with cold water and drain.
Roast the pine nuts without adding any fat, leave to cool.
Halve and core the grapes. Cut the leek into very fine strips. Set aside a little basil for the garnish, chop the rest.
Mix the oil, balsamic vinegar and grappa in a bowl. Season to taste with salt and pepper. Add the lentils, grapes and leeks, mix well. Let it steep for 10 minutes.
Spread the lettuce on plates, sprinkle with pine nuts and decorate with the rest of the basil.
It goes well with raw ham florets or Parmesan chips.
The grappa can also be left out, but gives a special kick.