How to Make It
Peel oranges and grapefruit; cut away bitter white pith. Cut each orange into 1/4-inch-thick rounds. Holding 1 peeled grapefruit in the palm of your hand, slice between membranes, and gently remove whole segments. Repeat with remaining grapefruit.
Whisk together orange juice and next 6 ingredients. Add oil in a slow steady stream, whisking constantly until smooth. Toss together kale, onion, and 1/2 cup dressing in a large bowl. Add salt and pepper to taste. Top salad with citrus, and sprinkle with cheese. Serve with remaining dressing.