Preheat the oven to 400 degrees F.
In a large roasting pan, spread the onions, leeks, mushrooms, carrots, celery, turnips, parsnips, squash, zucchini, tomatoes and garlic cloves. Drizzle with the olive oil, and season with the salt and pepper, stirring to coat. Roast for 45 minutes, stirring, every 15 minutes to brown evenly.
Remove from the oven and transfer to a large pot. Add the water and herbs, and bring to a boil. Reduce the heat and simmer for 20 minutes, skimming to remove any foam that rises to the surface. Add the wine and cook for 30 minutes.
Remove from the heat and strain through a fine mesh strainer into a clean container. Use immediately, cool in an ice bath, then refrigerate in an airtight container for up to 5 days. (The stock can be frozen for up to 3 months.)
Yield: about 1 gallon