Preheat the oven to 400 F. In a large bowl, whisk together the vinegar, olive oil and herbs. Add the sweet potatoes, squash and onion and toss until vegetables are well coated. With a slotted spoon (reserve liquid in the bowl), transfer the vegetables to a baking dish and spread them out in one even layer. Roast them in the oven for 40 to 45 minutes, until potatoes are tender and slightly brown and the vinegar mixture has evaporated to a thick glaze. Stir several times during the cooking. Meanwhile, in a large bowl, toss the tomatoes, red bell peppers, broccoli and green beans with the reserved liquid and spread them in one even layer in a separate baking dish. Roast them in the oven for 25 to 30 minutes, or until the skin on the tomatoes starts to shrink. In a large bowl, gentle toss all of the vegetables together with any remaining cooking liquid until just mixed. Season with salt and pepper; garnish with fresh herb leaves, if desired.
Serves 8 to 10
Variations: Cauliflower or Brussels sprouts can be used instead of broccoli; substitute any kind of potato for the sweet potatoes; and try sweet Italian peppers or banana peppers instead of the bell pepper. Acorn squash or pumpkin can be used in place of the butternut squash. Carrots, garlic and onions are a delicious addition any time of the year.