Peel and roughly chop 2 pounds carrots. Cook in boiling salted water until soft, about 20 minutes; drain. Puree with 3 tablespoons olive oil; season with salt and pepper. Warm 1 tablespoon olive oil with 1 teaspoon each grated ginger and orange zest; drizzle over the mash.
Use a food processor or immersion blender to puree these veggies-they're too fibrous for a potato masher.