Pre-heat the oven to 375 degrees. Remove the stems and leaves from the beets. Place the beets on a large piece of tinfoil and toss with a tablespoon of olive oil and season with salt and pepper. Tightly wrap the foil packet and place on a rimmed baking sheet. Bake the beets for 1 hour and 15 minutes or until they are easily pierced with the tip of a knife. Let cool slightly and then peel the skins off and slice into quarters.
Meanwhile, cook the quinoa. Rinse it well and then add it along with the 1 1/2 cups of water in a medium saucepan with a pinch of salt. Bring to a boil, reduce the heat to medium and cook for 15 minutes or until all the water is absorbed. Take off the heat, cover and let steam for 5 minutes.
Pour the remaining tablespoon of olive oil into a skillet over medium heat. Cut the beet stems into small pieces and add to the oil, cook for 3-4 minutes until they begin to soften. Slice the beet greens into ribbons and then add them to the pan along with the stems and season with salt and pepper. Cook for 3-5 minutes until the greens are wilted.
In a blender place all the ingredients for the dressing and process to combine, taste and add more salt or pepper if desired.
Divide the quinoa, beet greens and beets among four bowls. Top with a tablespoon or two of the tahini sauce and top with the fresh mint.