Preheat the oven to 400 °. Place the vegetables on a rimmed baking sheet. Brush the vegetables with the oil and season them to taste with salt and pepper. Roast the vegetables for 30 to 45 minutes, until tender and spotted with brown.
Scoop the eggplant pulp from the skin and place it in a large stockpot. Add the other vegetables, oregano, and bay leaf to the pot.
Add 4 cups broth and bring to a simmer. Simmer the mixture for 30 to 45 minutes or until the vegetables are very tender.
Remove the bay leaf and discard. Use an immersion blender to blend the vegetables until smooth. (You can also blend the soup in a blender or in a food processor.) Thin with more stock, if desired. Adjust the seasonings and serve hot.
Notes
Promptly store leftovers in an airtight container in the refrigerator, for up to 4 days.To freeze: chill the soup and store in meal- or individual-sized portions in the freezer, for up to 2 months. Reheat before serving.Nutritional values are approximate and based on ⅙ the recipe.Variations: Feel free to adjust the vegetables you use in Roast Vegetable Soup as well as the seasoning. Here are just a few ways you can adjust the flavor profile:
For Indian, add a hefty amount of garam masala and serve with naan.
Topping ideas: Add chopped green onions, fresh chopped herbs, chopped nuts, crumbled bacon, or even cooked shrimp atop this soup for a fun garnish. You can also top it with oyster crackers, broken saltines, or croutons as well as a drizzle of sour cream or sriracha.