Preheat the oven to 400 degrees F.
For the roasted beets: Place each beet on an individual piece of aluminum foil. Drizzle the beets with olive oil and season with salt and pepper. Fold into loose packets and place on a sheet pan. Roast the beets for 45-50 minutes until they can be easily pierced with a knife.
When the beets are cool enough to handle, use a towel to rub off the skins. Then cut the beets into a 1/2-inch dice.
For the oranges: Cut the skin and white pith from the oranges. Slice between the membranes removing the orange segments while collecting the juice in small bowl. Dice the oranges.
For the salad: In a large bowl, combine the beets, oranges, pears, blue cheese, pistachios, arugula and chives.
For the vinaigrette: Whisk the 3 tablespoons olive oil, champagne vinegar, garlic, chives, 1/2 teaspoon kosher salt and 1/2 teaspoon black pepper into the orange juice. Drizzle the vinaigrette into the salad.