Make the dressing: Combine green onion and vinegar in a small bowl, add pulverized chile flakes and walnuts and beat in mustard and honey. Beat in olive oil. Set aside.
Wash and roughly chop the kale and massage thoroughly with a bit of olive oil.
Peel and dice the apples and kohlrabis.
Make the salad: In a large bowl, combine apples and kohlrabi and mix with half the dressing. Fold in massaged kale, Parmigiano-Reggiano, walnuts and lemon juice. Add remaining dressing and mix. Season to taste with salt and pepper. Add ham to each serving if you're into it!