In a saucepan over medium heat, combine the blueberries, ¼ cup water, orange juice, and sugar. Stir gently, and bring to a boil. In a cup or small bowl, mix together the cornstarch and ¼ cup cold water. Gently stir the cornstarch mixture into the blueberries so as not to mash the berries.
Preheat oven to 425 degrees. On a large rimmed baking sheet, toss the carrots and parsnips with the butter, oil, and honey. Spread the vegetables in a single layer and season with salt and pepper. Roast the carrots and parsnips for about 35 minutes, or until tender.