Ingredients

• 1/3 cup extra-virgin olive oil
• 1/3 cup olive oil
• 1 tablespoon chopped fresh oregano
• 1 tablespoon chopped fresh Italian parsley
• 1 tablespoon chopped fresh rosemary
• 6 1-to 1 1/4-inch-diameter golden baby beets with green tops attached (about 1 bunch)
• 6 1- to 11/4-inch-diameter candy-canestriped (Chioggia) baby beets or golden baby beets with green tops attached (about 1 bunch)
• 1 2-pound butternut squash, peeled, halved, seeded, cut into 1/2-inch cubes (about 4 cups)
• 1 1/2 pounds russet potatoes, peeled, cut into 1/2-inch cubes (about 3 cups)
• 1 pound garnet yams or other yams (red-skinned sweet potatoes), peeled, cut into 1/2-inch cubes (about 2 cups)
• 1/4 cup (1/2 stick) butter, cut into 1/2-inch cubes

Instructions

1. Whisk all ingredients in small bowl. DO AHEAD: Can be made 4 days ahead. Cover and chill. Bring to room temperature and rewhisk before using.
2. Preheat oven to 350°F. Cut greens and stems off all beets; discard stems. Coarsely chop enough beet greens to measure 4 loosely packed cups. Bring medium saucepan of salted water to boil. Add greens and cook just until wilted, about 1 minute. Drain well. Set aside. Scrub beets; place in 8x8x2-inch glass baking dish. Pour half of herb oil over beets; sprinkle with salt and pepper. Cover baking dish with foil and roast beets until tender when pierced with small sharp knife, about 1 hour. Remove from oven and let beets stand until cool enough to handle. Peel beets; cut into 1/2-inch pieces and reserve. DO AHEAD: Beet greens and beets can be made 1 day ahead. Cover separately and chill.
3. Increase oven temperature to 375°F. Combine squash, potatoes, and yams in large bowl. Add remaining herb oil and toss to coat. Sprinkle generously with salt and pepper. Spread vegetable mixture evenly on large rimmed baking sheet. Roast until vegetables are tender when pierced with knife and lightly browned around edges, stirring and turning vegetables occasionally, about 50 minutes. DO AHEAD: Can be made 2 hours ahead. Let stand uncovered at room temperature. Rewarm in 350°F oven until heated through, about 15 minutes.
4. Stir beets and beet greens into roasted vegetables; dot with butter cubes and continue to roast just until beets are heated through, 5 to 10 minutes. Transfer vegetable mixture to large bowl and serve.