Preheat oven to 400 degrees F (200 degrees C). Line a baking dish with aluminum foil.
Place carrots, zucchini, and sweet potato in a large bowl; stir in olive oil, butter, lemon juice, and lemon zest until combined; season with salt and pepper. Pour vegetable mixture into prepared baking dish.
Bake in the preheated oven 10 minutes; toss mixture again. Continue baking until vegetables are tender, about 10 minutes more. Transfer vegetables to individual serving bowls; sprinkle with parsley.
