Whipped Potatoes and Kohlrabi

1/2 pound baking or russet potatoes (about 2 potatoes)
1 pound kohlrabi (about 4 bulbs)
3 to 4 tablespoons butter
¼ to ½ cup milk or cream
½ teaspoon salt, plus more, to taste
Black pepper to taste
• Boil the potatoes and kohlrabi separately until tender, 20 to 35 minutes, depending on size. Drain, reserving 1/2 cup of liquid from either vegetable.
•
• Peel potatoes and kohlrabi. Mash together in large bowl.
• Melt butter in small pot over medium heat. Add ¼ cup of the milk or cream. Heat until almost simmering, then remove from heat.
• Pour butter mixture over potato/kohlrabi mixture. Add ½ teaspoon salt and pepper to taste. Beat until fully combined and smooth. If you want it to be creamier, add up to ¼ cup additional milk or cream. If you want it to be smoother, stir in up to ½ cup of the reserved corking water until you like its consistency.
(From: John Peterson and Angelic Organics, Farmer John’s Cookbook)