You can definitely substitute some cabbage for the kohlrabi and regular green onion for the purple kind.
1 carrot, julienned
1 cucumber, peeled and julienned
1 small kohlrabi, peeled julienned
1 small beet, peeled and julienned
1 green onion, thinly sliced
1/4 cup buttermilk
1/4 cup greek yogurt (2%)
1 tablespoon lemon juice
Salt and pepper
To prepare the kohlrabi, make sure you remove the skin as well as the first layer of the vegetable because it will be tough. In a medium bowl, whisk together ingredients for the sauce. Adjust seasoning to taste. Add all julienned vegetables to the bowl, toss lightly. Cover and let sit in the fridge for an hour to allow the flavors to meld.