Clean, peel and wash the kohlrabi. Cut each kohlrabi into about 4 slices. Cover and cook in plenty of boiling salted water for about 5 minutes until al dente. Rinse briefly under cold water, drain and allow to cool.
In the meantime peel, clean and grate the carrots. Cut cress from the bed. Mix the carrots and cress with vinegar, except for a little for garnishing, and season with sugar, salt and pepper. Rinse lime with hot water, finely grate peel.
Halve the lime, squeeze the juice. Peel garlic and chop finely. Mix margarine, garlic and lime peel and juice, season with salt and pepper.
Wash parsley, shake dry and chop finely, mix with the panko. Whisk the eggs with 1 tbsp. cold water and some salt and pepper. Heat the oil in portions in a large pan. Turn kohlrabi slices first in flour, then in egg and finally in Panko.
Fry in hot oil for 3-4 minutes, turning each portion until golden brown. Keep warm.
Spread 4 slices of bread with the lime-garlic margarine. Place 2 kohlrabi roasts on each, spread carrot-cress salad on top and cover with the remaining slices of bread. Arrange on a plate and sprinkle with cress.