Crunchy apple and kohlrabi salad

This crisp and refreshing salad, which was inspired by the version served at Chez Ma Tante in Brooklyn, proves that the simplest version of a dish can sometimes be the best. The combination of very thinly sliced tart apple and crunchy, mild kohlrabi is perfectly harmonious, and soaking the onion in ice water mellows its sharp bite. At Chez Ma Tante, the salad is sometimes garnished with toasted hazelnuts and fresh herbs. Chervil is a great option but can be tricky to find; a bit of fresh parsley, tarragon or a combination makes a fine substitute. Using a mandoline to slice the ingredients super-thin gives the best results, but you can use a sharp chef's knife instead.