For the soup, set aside the tender kohlrabi leaves.
Peel the kohlrabi, core the apples, dice both. Peel and dice the onions. Heat oil, sauté prepared ingredients for about 5 minutes. Add stock, simmer for about 15 minutes.
Puree finely with a blender, season with mustard, salt, pepper and nutmeg.
For the pesto, rinse and dry the lemon, grate the zest.
Toast nuts in a pan with 50 ml oil on medium heat, then puree in a blender cup with 40 ml oil and lemon zest.
Rinse and dry chives, cut into small rolls, stir into pesto, season with salt and pepper.
Rinse apple, quarter, core, cut into sticks. Serve soup, drizzle some pesto and oil over it, sprinkle with apple sticks, cabbage leaves and pepper.