Place the vegetables except for the mushrooms on a baking sheet. Add salt on both sides and drizzle the olive oil all over the veggies. Roast the vegetables at 375 degrees F for about 40 minutes.
In a small bowl, combine the ingredients for the dressing and mix well. Taste it and adjust as needed. Pour the mixture over the roasted vegetables and add the mushrooms and olives.
When cooled, put the vegetables in the fridge to marinate overnight.
Take them out several hours before serving. Serve the vegetables at room temperature. Top with any remaining fresh herbs like mint.
The vegetables can be grilled rather than be cooked in the oven.
Mario Batali's recipe mentioned to leave the vegetables out on the counter to marinade overnight but I prefer to leave mine in the fridge overnight.
Feel free to substitute the vinegar for red wine vinegar, as well as the vegetables.