How to Make It
In a medium saucepan, bring 1/4 inch of water to a boil. Add the kale, cover and cook over moderate heat until wilted, 3 minutes. Drain the kale and cool slightly, then squeeze dry.
In a food processor, combine the kale, garlic, serrano, anchovy, yogurt, buttermilk, onion powder, cumin, dill and lemon juice and pulse to combine. With the machine on, slowly drizzle in the olive oil until a thick dressing forms. Season with salt and pepper. Transfer the dressing to a bowl and serve with roasted root vegetables.