MAKE THE SALAD:
Meanwhile, divide the carrots, parsnips and turnips between 2 large rimmed baking sheets. Toss the vegetables in each pan with 1 tablespoon of the vegetable oil. Arrange the onion wedges on the baking sheets, keeping them intact. Brush the onion wedges all over with the remaining 1 tablespoon of vegetable oil. Generously season the vegetables with salt and pepper. Roast the vegetables for 40 minutes. Brush the vegetables with the warm honey and sprinkle with the sage. Continue to roast the vegetables for 25 minutes longer, or until they are tender and glazed. Loosen the vegetables with a spatula and let them cool to room temperature in the pans.