Cut the kohlrabi leaves and reserve them for other uses (stock, wok, etc). Remove the hard parts of the skin leaving a smooth and uniform surface. Brush and wash the kohlrabi thoroughly to remove any dirt.
Using a mandolin (or vegetable peeler if you don't have one) cut the kohlrabi into very, very thin slices, ideally one millimeter thick.
Work the lemon zest and reserve it.
Put the kohlrabi slices in a bowl and with your hands, dress them with the juice of the lemon.
Spread the slices on a flat dish and dress with the olive oil to your liking. Season with salt and pepper, try a slice and correct the dressing if necessary.
Cut the black garlic into very thin slices and decorate the salad with them and with the lemon zest.
Recipe by The Quotidian Cook at https://www.thequotidiancook.com/en/kohlrabi-and-black-garlic-salad/