Remove the top and bottom of the kohlrabi, but you don't have to peel them. Peel the carrots and the apple. Peel the onion. Cut everything into pieces and sauté in olive oil for 2 to 3 minutes.
Add the chicken stock, so that the vegetables are covered. Let it cook until the vegetables are done.
Mix the soup and season with salt and pepper.
Poach the eggs. Bring water to just below the boil with a generous dash of vinegar. Crack the eggs into a cup and pour them one by one into the water. Poach for about 3 minutes. Pat dry.
Finely chop the lettuce. Finish the soup with the lettuce, duck breast and poached egg. Sprinkle with sesame seeds and olive oil.