Resting time: about 3 hours
For the lettuce, remove the withered leaves and the roots from the leeks, rinse and dry them and cut them into finger-length pieces.
Heat the oil. Sauté the leek in it over medium heat. Add salt, sugar and clear soup and bring to a boil. Leave the leek on the heat for about 3 minutes. Add the vinegar. Leave the leek salad to stand at room temperature with the lid on for 3 hours.
For the waffles, coarsely grind the wheat, mix with milk, sour cream, eggs, cheese, nuts, salt, thyme, pepper and nutmeg.
Just before eating, cut the cress into small pieces and sprinkle over the leek salad. Grease the baking surfaces of the waffle iron. Pour in about 1 1/2 tablespoons of batter at a time, close the iron and bake each waffle for 3 to 4 minutes.