Roast the beet the day before so they are ready for this quick meal.
Preheat oven to 350 degrees. Cut the beet greens from the beets. Stick the beet greens in a jar with some water, cover with a plastic bag and store in the refrigerator.
Place the beets themselves in a casserole dish with a lid. Add about 2 tablespoons of water to the dish. Cover and roast about 45 minutes, until the beets are tender enough to pierce with a fork. Let cool.
Wash the beet greens. Trim away the stems. Chop the greens in ribbons, about 1/2 –inch wide. Set aside.
Bring a large pot of water to a boil. Add several teaspoons of salt and stir in the tortellini.
Cook the tortellini according to the package instructions; for Trader Giotto’s tortellini it is 15 minutes.
Drain, saving about 1 cup of the pasta water.
Meanwhile heat the oil in a large skillet on low heat. Stir in the garlic and pepper flakes and cook, stirring about 5 minutes.
Place the beet greens on top, cover with a lid, and heat until the greens have wilted and shrunk, 5 to 8 minutes.
Slip the skins from about half of the roasted beets and cut them into pieces about ½-inch wide.
Stir the goat cheese into the greens and garlic, along with about 2/3 cup of the reserved pasta water, breaking it up with a spoon, and stirring to make a sauce.
Gently stir in the tortellini and the beet pieces and cook just until they are heated through, adding more pasta water if needed.
Season with salt to taste.
Sprinkle with the pumpkin seeds just before serving.