1. Trim stems from beet tops. Coarsely chop beet greens and set aside.
2. Place beets and 1/2 cup water in a deep microwave-safe baking dish. Cover and cook in microwave oven until tender (15-20 minutes).
3. While beets at cooking, cook spaghetti according to package directions.
4. Rinse beets under cold running water until cool enough to handle. Peel and cut into bite-sized pieces.
5. Heat oil in a large skillet over medium heat. Saute garlic and crushed red pepper until garlic is golden (1 minute).
6. Increase heat to medium-high and add beet greens, beets, and salt to skillet. Cook until just greens are just wilted and beets are warm (2-3 minutes).
7. Toss beets and greens with cooked spaghetti and serve warm.