Preheat oven to 400 degrees Fahrenheit. Line a baking sheet with Gefen Parchment Paper.

Spread mushrooms and zucchini on baking sheet and drizzle with two tablespoons oil. Roast for 15 minutes.

While the vegetables are roasting, heat remaining oil in a four-quart pot. Add onion and sauté for 10 minutes. Stir in the garlic. Add the roasted vegetables and stir in remaining ingredients. Bring to a boil, lower the flame and allow to simmer for 30 minutes.

Blend with an immersion blender.