Cook the lentils according to package instructions. (I cooked mine in vegetable broth for more flavor)
Preheat oven to 400 degrees and line a rimmed baking sheet with foil.
Peel the beets with a vegetable peeler and cut them into wedges.
Place the beets on the prepared baking sheet, drizzle them with olive oil, salt and pepper and toss to coat.
Spread the beets into a single layer then roast them for approximately 25-30 minutes minutes or until tender, shaking the tray and tossing them around a couple of time to ensure even cooking.
Remove from the oven and cool while you assemble the salad.
In a large bowl add the mixed greens.
Top with the beets, oranges, lentils, pomegranate seeds and pistachios.
Serve the orange vinaigrette on the side or dress the salad right before serving to ensure all the ingredients stay crisp.