Peel the kohlrabi bulbs, making sure to remove any woody parts. Chop into small, bite sized pieces
Select the most tender kohlrabi leaves and slice them into thin strips.
Chop the onion and place it in a stock pot with the butter. Sauté the onions on medium heat for 3-5 minutes. Then add the sliced kohlrabi leaves and chopped bulbs and sauté another 3-5 five minutes.
Add the vegetable broth/chicken stock, milk and bay leaf. Bring to a boil and then cover, reduce to a simmer. Cook until the kohlrabi is tender which takes about 20-30 minutes.
Remove the bay leaf and add salt and pepper to taste. Serve with your favorite bread.