Remove stems and leaves from beets, discarding stems. Coarsely chop leaves; set aside.
Place each beet on a piece of aluminum foil. Drizzle each evenly with 1 teaspoon olive oil, 1/4 teaspoon salt, and 1/4 teaspoon pepper. Wrap beets tightly in foil.
Bake at 375° for 1 1/2 hours or until tender. Cool slightly; gently rub beets to remove skins. Cut beets in half lengthwise, and thinly slice into crescents.
Meanwhile, heat remaining 1 1/2 teaspoons olive oil in a large nonstick skillet over medium-high heat. Add garlic, and sauté 1 minute. Add greens and remaining 1/4 teaspoon each of salt and pepper; sauté 2 to 3 minutes or until wilted and tender.
Toss cooled beets with greens and vinaigrette. Cover and chill several hours or until ready to serve. Sprinkle with walnuts and goat cheese before serving.